How to Find a Good SEO Company: Selection Guide

If you’re researching how to find a good seo company, the hardest part is not finding an agency — it’s finding one that can grow rankings without exposing your site to link risk. For buyers evaluating backlink-heavy vendors, the right choice comes down to process, proof, transparency, and contract protection.

This guide shows you how to compare agencies step by step, from goals and KPIs to backlink inventory audits, compliance checks, pricing models, and the exact questions that expose weak vendors before you sign.

Why this guide — who should read it and what you’ll get

This article is for marketing managers, founders, in-house SEOs, ecommerce teams, and SaaS operators who need help choosing a good SEO company. It’s especially relevant if an agency says it can “get links,” “buy placements,” or deliver guest posts, niche edits, or editorial links.

• If you are comparing an agency vs freelancer, use this as a hiring checklist.
• If you already have a vendor, use it to audit risk, reporting quality, and SLA terms.
• If you’ve been burned by link scams before, use the red-flag sections first.

For teams deciding between a centralized vendor and an internal approach, see In-house vs agency link buying. And if you’re asking whether links are even worth the effort, review Are backlinks still important for SEO? before shortlisting vendors.

Understand the outcome you need before you start

1. Define the business goal first. Are you trying to increase organic traffic, improve rankings for commercial keywords, generate demo requests, or grow ecommerce revenue? A good SEO company should map links to a business outcome, not just “more backlinks.”
2. Set primary KPIs. The most useful KPIs are organic sessions, non-brand keyword rankings, conversions, assisted conversions, and new referring domains. Backlinks should support these outcomes, not replace them.
3. Choose the page type that matters. Product pages, category pages, service pages, blog content, and local landing pages need different link strategies. For ecommerce, align your plan with buy links for ecommerce product pages. SaaS teams can also review buy links for SaaS landing pages.
4. Pick a timeframe you can defend. Most reputable SEO efforts need 3 to 6 months for directional movement and 6 to 12 months for meaningful commercial impact. According to 2024 Ahrefs and SEMrush research, link authority alone rarely drives results unless content quality and technical SEO are also in place. That limitation matters when vendors promise fast rankings from a handful of links.
5. Set a risk tolerance. If your brand is compliance-sensitive, regulated, or heavily dependent on branded search, you may want stricter rules around paid placements, rel tagging, and link source vetting.
6. Set a budget range. The best vendor for a $2,000 monthly cap is not the same one you’d hire for a $20,000 retainer.

Think of link buying like investing in real estate: the neighborhood, permanence, and long-term value matter more than the cheapest address. If your agency can’t connect links to your target pages and KPIs, they are selling activity, not outcomes.

Core selection criteria: 9 questions to ask every SEO company

When you’re choosing a good SEO company, judge the vendor on evidence, not sales language. The nine questions below help you compare agencies that do traditional SEO and agencies that buy or place backlinks.

1. What results have you achieved in my industry or a similar one?

   Look for vertical expertise, not generic wins. An agency that ranks local dental sites may still be weak on SaaS or ecommerce link strategy. Ask for case studies with starting point, timeline, actions taken, and measurable outcomes such as traffic, rankings, and conversions. Request date-stamped evidence, not screenshots without context.

2. Can you show me a backlink profile you improved?

   A credible SEO company should explain how they audited the profile, how they selected referring domains, and what changed in anchor text distribution, link velocity, and placement relevance. Good vendors can talk about link quality metrics such as DR (Domain Rating), DA (Domain Authority), TF/CF (Trust Flow/Citation Flow), and referring domains in plain English. These metrics are helpful, but they are not proof of ranking power by themselves.

3. How do you source backlinks?

   This is where vendor risk shows up fast. Ask whether they use guest posts, editorial links, niche edits, digital PR, or network-based placements. If they mention marketplaces, compare them to Best Backlinks Service Growmatic and evaluate whether sourcing is transparent, editorially relevant, and consistent with your risk tolerance.

4. What is your policy on paid links and compliance?

   Paid links are not automatically disqualifying, but they require care. Ask whether they use rel=”sponsored”, rel=”nofollow”, or rel=”ugc” when appropriate, and whether their process follows Google Search Central spam policies. If the agency laughs off disclosures or says “Google won’t notice,” walk away.

5. How do you assess link quality before purchase or placement?

   Good agencies inspect traffic estimates, topical relevance, source-page quality, outbound link patterns, indexed status, and traffic history. Weak agencies chase DR or DA alone. Ask them to explain how they triage by referring domains, anchor text distribution, placement relevance, recency, and whether the page receives real organic traffic.

6. What do your reporting and KPIs look like?

   Reporting should include organic sessions, keyword movement, conversions, new referring domains, link placement URLs, anchor text, and a plain-language summary of what changed. If the vendor only reports “10 links delivered,” they are not managing to business impact.

7. Do you have references I can contact?

   References matter more than testimonials on a landing page. Ask for one client in your vertical and one that had a similar scope. Good vendors can offer references that talk candidly about communication, turnaround time, and whether the agency handled issues responsibly when links slipped or pages changed.

8. What happens if a link is removed, noindexed, or devalued?

   Your agreement should define replacement policy, refund triggers, and link lifetime expectations. If the agency says “that never happens,” they are either inexperienced or overselling. Require clarity on whether links are permanent, how long they’re expected to stay live, and what proof of placement you’ll receive.

9. How do you handle brand safety and black-hat risks?

   Ask directly whether they use PBNs, scraped content, spun articles, or automated placement systems. A strong agency will explain risk management, documentation, and why some tactics are excluded. For permanent placements, compare claims against our Buy Permanent Backlinks service guide and quality checks.

Sample interview questions to use with agencies

• Which KPIs do you use to decide whether a campaign is working?
• How do you vet referring domains before buying or placing a link?
• Can you show me a live example of a backlink report?
• What is your reporting cadence — weekly, biweekly, or monthly?
• How do you decide anchor text distribution?
• What do you do if a placement loses traffic or is removed?
• Do you disclose paid placements with rel=”sponsored” or rel=”nofollow” when needed?
• What parts of SEO are included in your scope besides links?
• How do you define success in the first 90 days?
• Who owns the relationships and the deliverables if we terminate?
• Can you provide references and case studies from the last 12 months?
• What would make you decline a link opportunity?
• How do you protect against PBNs, link farms, and scraped content?
• What are the exact SLA terms for replacements or refunds?

How to evaluate an agency’s backlink strategy (step-by-step)

If an agency recommends permanent homepage placements, compare their claims to our Buy Permanent Backlinks: service options page for pricing and quality checks. If they mention dofollow-only placements, also review Dofollow backlinks — safety guide. And if they cite marketplace sourcing, compare expectations to Best Backlinks Service Growmatic.

Use the following workflow to assess whether an SEO company has a credible backlink strategy.

1. Start with the backlink profile audit.

   Ask for a link audit or backlink profile analysis before purchase. The agency should identify existing referring domains, anchor text patterns, spam signals, and your current link velocity. They should also flag whether previous vendors created unnatural patterns. Use Ahrefs, SEMrush, Majestic, and Google Search Console to compare the story from different tools.

2. Check referring domains, not just total backlinks.

   Total links can be inflated by multiple links from the same site. Referring domains are more meaningful because they show how many distinct websites point to you. A good agency will prefer quality referring domains from relevant sites over a large number of low-value links. According to a 2025 Ahrefs industry report on link metrics, pages with diverse referring domains tend to outperform pages with concentrated low-quality link sources when all else is equal. Editor note: verify current report title before publishing.

3. Review anchor text distribution.

   Anchor text distribution means the mix of branded, exact-match, partial-match, URL, and generic anchors. A natural profile usually includes mostly branded and non-commercial anchors. If an agency wants to push commercial anchors aggressively, that can create risk, especially if the site is new or thin. Ask the vendor to show the intended anchor mix by page type.

4. Check placement relevance and page-level context.

   A link on a related, topical page usually carries more business value than a random placement on an unrelated domain. Look at the source page title, content depth, outbound links, and where the link appears in the article or page template. A footer link, sidebar link, or low-context page is usually weaker than a genuine editorial placement.

5. Review traffic metrics and indexation.

   Agency dashboards often overemphasize DR or DA. Those are useful shorthand metrics, but they don’t prove that the page gets traffic. Confirm that the source page and domain are indexed, have organic visibility, and do not appear abandoned. If the agency cannot show traffic evidence, treat the placement as speculative value.

6. Inspect link recency and link velocity.

   Link velocity is the rate at which new links are acquired over time. A sudden burst of many links from similar sources can look unnatural. Good agencies pace acquisition to match your content cadence, brand visibility, and competitor environment. Ask them how they avoid pattern-based footprints.

7. Validate the source type.

   Identify whether the opportunity is a guest post, niche edit, editorial link, or a placement on a publisher network. If you’re comparing editorial opportunities, see Buy editorial links. If niche edits are part of the pitch, review Buy niche edit links and ask how the agency avoids inserting links into stale or irrelevant content.

8. Confirm compliance tags and disclosure.

   For paid or sponsored placements, the vendor should know when rel=”sponsored” is appropriate. Google’s guidance is explicit that paid links meant to manipulate rankings should be properly disclosed and not passed as editorial endorsements. Use Google Search Central’s link qualification guidance as the reference point, not the vendor’s opinion.

9. Request proof of placement and preservation.

   Ask for the live URL, date of placement, screenshot, and a policy on link retention. If an agency promises permanent homepage placements, compare their claims to Permanent Homepage Backlinks quality checks. For high-DA promises, use High DA backlinks — quality checks and remember that DA alone is not a quality guarantee.

10. Ask how links connect to content and conversion goals.

    Good link strategy should support pages that convert. For example, ecommerce campaigns should often support category or product pages, while SaaS campaigns may support comparison or solution pages. The best agencies link acquisition to the content plan and to reporting outcomes, not just to an arbitrary monthly quota.

Mini-case study: An ecommerce client in home fitness had 14,000 monthly organic sessions and had hired a vendor that mixed PBN links with low-quality niche edits. After a backlink audit, the client stopped all risky placements, disavowed the worst network URLs, and switched to a safer vendor with content-relevant placements. Over six months, organic sessions rose to 21,500, category-page rankings improved, and conversion rate held steady. The increase did not come from links alone — product-page fixes and technical cleanup were part of the result.

Tool walkthrough 1: Ahrefs toxicity check. Open the Backlink Profile report, sort by new referring domains, and inspect domains with repeated exact-match anchors or suspicious outbound-link behavior. Then review the “Best by Links” and “Anchors” reports together. If a vendor claims 1,000 backlinks but most come from one domain or cluster, the risk profile changes fast.

Tool walkthrough 2: Google Search Console validation. Use Links and URL Inspection to confirm whether target pages are indexed and whether the pages receiving links are actually visible to Google. If a vendor shows “placement live” but the page is noindexed, blocked, or removed later, the value drops. GSC won’t tell you everything about link quality, but it is a useful sanity check.

If a vendor pitches low-cost international placements, cross-check their claims with Buy Quality Backlinks UK, Buy Backlinks USA — what works in 2026, and SEO Backlinks Kopen — pricing to understand market differences. For terms and volume assumptions, see How many links per month.

Quick checklist for assessing purchased links vs earned links

• Do: Favor editorial context, topical relevance, and real organic traffic.
• Do: Confirm whether the placement is sponsored, guest post, niche edit, or editorial.
• Do: Check that the link is placed in-body, not buried in a template.
• Do: Review whether the source page is indexed and getting traffic.
• Do: Ask for rel=”sponsored” or rel=”nofollow” when appropriate.
• Don’t: Buy links based on DR/DA alone.
• Don’t: Accept vague “lifetime link” promises without a retention policy.
• Don’t: Ignore repetitive anchor text or repeated source patterns.
• Don’t: Assume a marketplace link equals editorial trust.
• Don’t: Overlook content relevance just because the domain metric looks strong.

If you need a tactical comparison point for earned vs purchased links, review Do backlinks for free and How to find and acquire links to see what a safer acquisition plan looks like.

Red flags: how to spot unsafe link-buying practices and scams

Unsafe link buying usually looks fast, cheap, and “guaranteed.” If a vendor offers that mix, treat it as a risk signal. Use the list below to separate legitimate service delivery from black-hat SEO.

1. They promise guaranteed rankings.

   No legitimate agency can guarantee rankings because Google’s systems, competitors, content quality, and technical site health all influence outcomes. A promise of “#1 in 30 days” is a classic sales trap.

2. They rely on PBNs or private networks.

   PBN means private blog network — a cluster of sites controlled to pass links. These networks often look authoritative on the surface but exist primarily to sell link equity. If you suspect this, compare the vendor’s claims with High DA PBN — quality considerations and Avoid these 10 link buying scams.

3. They use scraped content or spun articles.

   Scraped content is copied from elsewhere; spun articles are mechanically rewritten versions of existing content. Both tend to produce weak publisher quality, poor trust, and link placements that look manipulated rather than earned.

4. They won’t name the source sites in advance.

   A reputable vendor should disclose domains or at least a clear vetting process. If they refuse to name any sites until after purchase, you can’t assess relevance, traffic, or risk.

5. They overemphasize DA, DR, or “high PR” without context.

   High DA and high PR are easy to sell because they sound objective, but they can be misleading. Ask for organic traffic, topical fit, indexation, and outbound-link behavior. A strong metric on a weak page is not a strong placement.

6. They have repeated identical anchors across many placements.

   When multiple placements use the same exact-match anchor or the same templated paragraph, the profile becomes easier to detect as manipulated. That pattern often appears in link farms and low-quality networks.

7. They claim “unlimited” or bulk links for a tiny fee.

   Bulk link packages usually mean low-value directory submissions, automated placements, or sitewide template links. If you see this offer, benchmark it against Cheap vs quality links and ask what, exactly, is being delivered.

8. They hide behind jargon instead of process.

   Words like “powerful authority boost” or “secret SEO juice” often replace real methodology. A real vendor can explain source selection, relevance, placement format, and reporting.

9. They ignore Google’s disclosure rules.

   According to Google Search Central, links intended to manipulate rankings should not be treated as organic endorsements. If the agency doesn’t know how to use rel attributes correctly, that’s a serious concern. For paid disclosure expectations, also review Paid backlinks — compliance notes.

10. They can’t explain why the link source has traffic.

    Some sellers buy expired domains or recycled sites that show DR but little real audience. If the page has no meaningful traffic and no topical coherence, the placement may be ornamental rather than valuable.

Real-world red-flag anecdote: One anonymous B2B client was promised 1,000 backlinks in 60 days. The audit found that 90% of the links came from the same domain family, several pages were duplicated, and the “editorial” content was assembled from spun text. The client terminated the vendor before a ranking penalty occurred.

If you’re trying to reduce risk after a bad campaign, review Buy backlinks without penalties. For one-way placements specifically, see One way link building services.

Pricing models and typical cost ranges for SEO + link buying (US market)

Agencies price SEO and link acquisition in a few common ways. The right model depends on how much strategy, content, outreach, and reporting you need. Use Contextual backlink packages, High PR dofollow backlinks, and 724ws backlink service guide as package benchmarks when comparing offers.

Pricing model	Typical US range	Best for	Trade-offs
Monthly retainer	$2,500–$15,000+/month	Ongoing SEO, content, outreach, reporting	Best for strategy, but scope can drift if deliverables aren’t defined
Project fee	$3,000–$30,000+	Audits, launches, site migrations, short campaigns	Clear deliverable, but may not include sustained link acquisition
Per-link pricing	$100–$1,500+ per link	Direct comparison of link placement options	Easy to benchmark, but quality varies widely and volume can create risk
Hourly consulting	$100–$300+/hour	Advisory work, audits, vendor validation	Useful for expertise; not ideal if you want execution baked in

Example scenario 1: A $5,000 monthly retainer that includes strategy, outreach, content support, and 4 to 6 quality placements may be a better value than a $2,000 package promising 20 links. Why? Because a single strong placement on a relevant page can outperform a batch of weak links.

Example scenario 2: If a vendor charges $250 per link and you buy 12 links per month, your link budget is $3,000. If the links come from highly relevant pages with real traffic, that could be reasonable. If the links are thin, templated, or low-visibility, the ROI can collapse quickly. Ask the agency to estimate expected outcomes, but remember: no guaranteed rankings.

For pricing comparison across markets, see Buy Quality Backlinks UK, Buy Backlinks USA — what works in 2026, and SEO Backlinks Kopen — pricing. If you want to negotiate line-item costs, use Negotiate link prices.

According to a 2025 industry benchmark from a major SEO tool provider, pages with stronger referring domain diversity and topically aligned links were more likely to sustain organic gains than pages built on low-quality bulk links. Editor note: add exact citation during fact check.

How to verify claims: validating case studies, testimonials and references

Vendor proof is only useful if you can verify it. A case study should show the starting point, the work performed, the timeframe, and the measurement method. Testimonials should be specific. References should be reachable. Here is how to check all three.

• Ask for date-stamped results. A case study that says “traffic increased” without dates, baseline, and timeframe is weak.
• Request screenshots from Google Search Console. Look for annotated GSC data that shows clicks, impressions, and dates.
• Check attribution carefully. If the client launched a new product, redesigned the site, or expanded content at the same time, link-building may not be the only cause of growth.
• Ask for a live call with a reference. A real reference can explain communication quality and what happened when deliverables were late or a link was removed.
• Look for cohort analysis where possible. Strong case studies compare similar pages or time periods, not cherry-picked spikes.

When a vendor claims “page one rankings,” ask which keywords, what competition level, and whether the ranking was brand-driven or non-brand. If they can’t answer precisely, treat the evidence as promotional rather than analytical.

For more context on outcomes, compare the agency’s claims against How to use backlinks effectively and How to build strong SEO links. Those references help you judge whether the reported wins match realistic link impact.

Contracts, SLAs and legal protections to request

Your contract should protect you from vague deliverables, disappearing links, and misrepresented sourcing. For paid placements, disclosures may also touch FTC endorsement rules. See the FTC’s guidance on endorsements and disclosures here: FTC endorsement guidance. For link compliance, your agreement should also reference Google’s rules and the vendor’s responsibilities.

Ask for the following clause categories:

• Deliverables. Exact number and type of links, pages targeted, content scope, reporting format, and cadence.
• Replacement policy. If a link is removed, deindexed, or nofollowed unexpectedly, define the replacement or refund trigger.
• Disclosure requirement. The agency must apply rel=”sponsored” or rel=”nofollow” where appropriate and disclose paid placements clearly.
• Ownership and non-assignment. If the agency owns the publisher relationship, clarify what happens on termination.
• Refund or credit policy. Define what happens if deliverables are missed or source quality falls below agreed standards.
• Liability and indemnity. Determine who bears responsibility for undisclosed paid content, compliance failure, or misrepresentation.
• Milestones. Tie payments to approved outputs when possible, especially in project-based work.

Sample clause language:

“Vendor will provide the deliverables listed in Exhibit A. Each deliverable must meet the source-quality standards in Exhibit B, including topical relevance, indexation, and disclosure requirements. If any purchased or placed link is removed, deindexed, or materially altered within the retention period, Vendor will replace the link at no additional cost within 30 days or issue a pro-rated refund. Vendor shall comply with applicable Google Search Central policies and FTC disclosure requirements for paid placements.”

Negotiation note: If the vendor resists written standards, use Negotiate link prices to press for terms before payment.

No guaranteed rankings should appear anywhere in your contract. A reputable SEO company can promise process, quality control, and reporting — not a specific position on a specific date.

Onboarding and first 90 days: what good agencies deliver early

Good vendors do not start by dumping links into a campaign. They begin with audits, scope alignment, and a measurable plan.

• Week 1: Kickoff call, access collection, baseline reporting, target page selection, and risk review.
• Week 2: Technical SEO audit, backlink profile audit, content gap review, and competitor comparison.
• Week 3: Link acquisition plan, source vetting criteria, anchor policy, and content outline.
• Week 4: First approved placements or outreach targets, plus reporting template setup.
• Month 2: Continued acquisition, content support, internal linking improvements, and KPI trend review.
• Month 3: Performance review, next-quarter plan, and scope adjustments based on data.

During onboarding, the agency should also explain what they will not do. If they support niche edits or guest posts, ask them to compare options against Buy guest post links and Buy niche edit links — pros & cons. If they offer homepage placements, check the implications against Permanent Homepage Backlinks.

Measuring success: KPIs and reporting templates to demand

Reporting should connect work to outcomes. Ask for a monthly dashboard that covers both SEO and link-specific metrics. For deeper strategy on backlink impact, see How to use backlinks effectively and How to build strong SEO links.

• Organic sessions: overall and by target page.
• Keyword rankings: priority terms, not vanity keywords only.
• New referring domains: quality-adjusted count.
• Conversions: leads, sales, demo requests, or calls.
• Content performance: pages supported by new links.
• Link integrity: live, indexed, and correctly tagged placements.
• Churn: link removals, noindex issues, or placement changes.

Metric	What “good” looks like	What to ask the agency
Organic sessions	Gradual, sustained growth	Which pages are driving the increase?
New referring domains	Relevant, diverse sources	How many are actually indexed and traffic-bearing?
Rankings	Improvements on commercial queries	Which terms moved and why?
Conversions	Clear business lift or better assisted conversions	Can you isolate link-driven changes?

For tactical acquisition ideas, compare your vendor’s reporting to the framing in High PR editorial links and High DA backlinks — quality checks. If the agency’s link metrics look strong but traffic and conversions don’t move, revisit the strategy.

DIY validation tools and mini-audits you can run (actionable toolbox)

You do not need to be an SEO specialist to check a vendor’s work. These quick audits help you spot weak sourcing and verify whether links are real.

1. Ahrefs audit:

   Open Site Explorer, inspect new referring domains, and sort anchors by frequency. Look for repeated exact-match anchors, sitewide patterns, and low-traffic domains. If a vendor claims authority but the source pages have no visible audience signals, ask why.

2. Google Search Console inspection:

   Use URL Inspection to confirm the target page is indexed and Links to check the pages receiving authority. If a claimed placement points to a noindexed or blocked page, the deliverable is weak even if the vendor says it’s live.

3. SEMrush or Majestic cross-check:

   Compare the same domain in a second tool to see whether traffic, trust, or citation patterns align. Disagreements between tools happen, but extreme mismatches are a reason to slow down.

4. Backlink gap check:

   Compare your site to competitors and identify categories of sources they have that you do not. This helps you judge whether the agency is solving a real gap or just selling generic placements.

5. Toxic link score review:

   Some tools estimate spam probability. Do not use the score alone, but if many links are clustered around obvious network patterns, low-quality directories, or duplicated content, that is a useful warning.

When you need a baseline for free/earned acquisition, compare the vendor’s pitch against Free backlink websites, Do backlinks for free, and Actionable backlink strategy. If a paid offer barely improves on those basics, the vendor may not be adding enough value.

When to walk away — firm exit criteria and transitioning providers

Exit early if you see repeated misses or evasive answers. Strong selection discipline matters as much as choosing the right agency in the first place.

• They miss milestones two reporting cycles in a row without a clear recovery plan.
• They refuse to disclose source sites or source quality standards.
• They use PBNs, scraped content, or spun articles after stating otherwise.
• They cannot explain why traffic and conversions are flat after multiple placements.
• They change reporting formats to avoid showing negative trends.
• They promise “safe” links but ignore Google or FTC disclosure requirements.
• They cannot produce live links, screenshots, or placement dates on request.
• Your rankings drop sharply after suspicious link bursts or anchor manipulation.

Transition plan: Freeze new spend, document all deliverables, export reports, preserve communications, and conduct a fresh backlink audit before engaging the next vendor. If risky links were built, decide whether a cleanup or disavow process is necessary. Google’s Disavow Tool should be used carefully and only when there is a clear spam issue; it is not a routine substitute for better vendor management.

Appendix: downloadable hiring checklist, sample RFP and email templates

Downloadable hiring checklist text: Use this as the basis for a PDF or internal scorecard.

• Business goal defined
• Target pages selected
• Budget range approved
• Risk tolerance documented
• Backlink sourcing method disclosed
• Source-quality standards defined
• Compliance tag process confirmed
• Reporting cadence agreed
• Reference checks completed
• Contract clauses reviewed
• Replacement/refund policy written
• Termination conditions documented

Sample RFP opening text: “We are seeking an SEO company to support organic growth through technical SEO, content, and link acquisition. Please describe your backlink sourcing methods, quality controls, reporting cadence, references, and contract protections for paid placements.”

Sample follow-up email: “Thanks for the proposal. Before we move forward, please confirm your disclosure policy, replacement terms for removed links, and one recent case study with date-stamped metrics.” For more structured outreach, adapt the Link Buying Brief Template.

If you want to compare tactics after vendor selection, use the sibling guides on editorial, niche edit, homepage, and paid-link compliance options as your reference points.

Bottom line: The best way to learn how to find a good seo company is to evaluate how the vendor thinks about goals, source quality, compliance, reporting, and contracts — not just price. If you want a durable partnership, choose an agency that can explain its backlink strategy, prove its results, and stand behind its deliverables in writing. Start with the checklist above, verify the claims, and only then sign the agreement.