7 Must-Check Metrics Before Buying a Guest Post

Buying a guest post in 2025? 🚨 STOP. Before you hand over your credit card, you need to run a full diagnostic on the website. One bad link can tank your rankings, trigger a Google penalty, or — at best — waste your money and time.

Forget what you’ve heard. “High DA” alone means nothing. A DA 80 site in the wrong niche is worse than a DA 40 site that’s perfectly relevant. Google’s algorithms now prioritize topical authority, E-E-A-T, and contextual relevance over vanity metrics.

In this no-fluff guide, you’ll learn the 7 non-negotiable metrics to check — backed by Google’s Quality Rater Guidelines, Ahrefs data, and real-world case studies. Plus, you’ll get a free checklist and tool recommendations to automate your vetting process.

👉 New to guest posting? Unable to find Guest Posts, Here is detailed guide onfinding guest post opportunities and why manual search fails.

📋 Table of Contents

Metric #1: Domain Authority (DA) – The Popularity Metric (Use With Caution)
Metric #2: Page Authority (PA) – The Page-Level Power
Metric #3: Domain Rating (DR) – Ahrefs’ Authority Score
Metric #4: Spam Score – Your #1 Red Flag Detector 🚩
Metric #5: Domain Age – Trust Built Over Time
Metric #6: Backlink Profile – Quality of Neighbors Matters
Metric #7: Topical Relevance – The King of All Metrics 👑
How to Check These Metrics (Free & Paid Tools)
The Ultimate Checklist: Should You Buy This Guest Post?
Trusted Resources & Further Reading

Metric #1: Domain Authority (DA) – The Popularity Metric (Use With Caution)

What it is: A Moz proprietary score (1-100) that predicts a website’s ability to rank. It’s based on the site’s overall link profile.

Why it matters: DA is a useful benchmark, but it’s not a Google ranking factor. Many sites artificially inflate DA using PBNs or spammy directories. Don’t be fooled by a big number.

✅ What to look for:

Ideal Range: DA 30+ for most niches. DA 50+ for competitive industries (finance, health, SaaS).
Red Flag: DA below 15 often indicates a new, low-quality, or spammy site.
Pro Tip: Cross-reference DA with DR and Spam Score. A high DA with a high Spam Score is a scam.

“Relevance > DA. A contextual link from a DA 40 niche site is infinitely more valuable than a link from a DA 80 site about casino gambling.” — Search Engine Journal, 2025

Metric #2: Page Authority (PA) – The Page-Level Power

What it is: Also from Moz, PA predicts how well a specific page will rank. It’s more granular than DA.

Why it matters: The page where your guest post will live might be on a high-DA site but buried in a low-traffic, low-authority section. PA tells you if that specific page has any SEO juice to pass on.

✅ What to look for:

Ideal Range: PA should be within 10-15 points of the site’s DA. A huge gap (e.g., DA 60, PA 20) means the page is weak and won’t pass much value.
How to Check: Use the free MozBar browser extension to check PA on the exact page where your link will appear.

Metric #3: Domain Rating (DR) – Ahrefs’ Authority Score

What it is: Ahrefs’ equivalent to DA, also scored 1-100. It measures the strength of a website’s backlink profile based on the number of unique domains linking to it.

Why it matters: Different tools, different algorithms. Cross-referencing DA with DR gives you a more holistic, trustworthy view. A site with high DA but low DR likely has low-quality links.

✅ What to look for:

Consistency is Key: DA and DR should be relatively close (±10 points). A large gap warrants deeper investigation.
Authority Signal: A high DR indicates the site is seen as a valuable resource by other publishers. This is a strong trust signal for Google.

Metric #4: Spam Score – Your #1 Red Flag Detector 🚩

What it is: A Moz metric (1-17%) that flags websites exhibiting characteristics commonly found in spammy sites (e.g., excessive ads, thin content, unnatural link profiles).

Why it matters: This is your first line of defense. Google’s algorithms are designed to devalue or penalize links from spammy neighborhoods. Associating with such a site can drag your own rankings down.

✅ What to look for:

🟢 Green Zone (Safe): 1% - 5%
🟡 Yellow Zone (Investigate): 6% - 30%
🔴 Red Zone (AVOID): 31%+ — Do not buy a link here.

“According to Moz, over 63% of sites advertising ‘DA 70+ guest posts’ have a Spam Score above 30 — meaning they’re high-risk for Google penalties.” — GuestPostOn Research, 2025

Metric #5: Domain Age – Trust Built Over Time

What it is: How long the domain has been registered and active.

Why it matters: Google’s “Page Age” patent suggests that older websites tend to rank higher due to accumulated trust, traffic, and quality backlinks. An old domain with a clean history is a strong signal of legitimacy.

✅ What to look for:

Minimum Threshold: Avoid sites younger than 1 year. They haven’t had time to build authority or prove their longevity.
Ideal: 3+ years old. The longer, the better, provided the site is actively maintained and updated.
How to Check: Use a free Whois lookup tool.

Metric #6: Backlink Profile – Quality of Neighbors Matters

What it is: An analysis of the websites linking to your target site. Who are their friends?

Why it matters: Google’s “Propagation of Trust” principle means a site’s reputation is influenced by its neighbors. If a site is linked to by spam blogs, PBNs, or irrelevant sites, its own authority is suspect.

✅ What to look for:

Anchor Text Diversity: Natural profiles have a mix of branded, generic, and keyword-rich anchors. Avoid sites with 80%+ exact-match keyword anchors — it’s a sign of manipulation.
Link Sources: Are the backlinks coming from reputable, editorial sites, or from low-quality directories and link farms?
“Link Neighborhood”: Use Ahrefs or SEMrush to see the top 10 linking domains. Do they look trustworthy and relevant?

Metric #7: Topical Relevance – The King of All Metrics 👑

What it is: How closely the website’s core topic aligns with your own niche and the content of your guest post.

Why it matters: This is the MOST CRITICAL factor. Google’s semantic search and E-E-A-T guidelines prioritize context and expertise. A link from a relevant site passes “topical authority,” telling Google you are an expert in that specific field. An irrelevant link is, at best, ignored, and at worst, seen as manipulative.

✅ What to look for:

Content Audit: Read 5-10 articles on the site. Is the content high-quality, well-researched, and on-topic?
Audience Match: Would your ideal customer be reading this site?
Entity Alignment: Does the site cover the same core entities, concepts, and questions as your own content? (e.g., If you sell CRM software, a site about “SaaS marketing” is relevant; a site about “organic gardening” is not).

“Topical relevancy is key: If you’re writing about Germany, internal links related to Germany or German cities should be placed in higher prominence sections.” — Semantic SEO Case Study

How to Check These Metrics (Free & Paid Tools)

You don’t need a massive budget to do your due diligence. Here’s your quick toolkit:

Metric	Free Tools	Paid Tools (Recommended)
DA / PA / Spam Score	MozBar (Browser Extension)	Moz Pro
DR / Backlink Profile	Ahrefs Webmaster Tools (Free limited version)	Ahrefs, SEMrush
Domain Age	Whois Lookup (e.g., whois.domaintools.com)	Any paid SEO tool (Ahrefs, SEMrush, Moz)
Topical Relevance	Manual review, Google search	MarketMuse, Clearscope (for content gap analysis)

The Ultimate Checklist: Should You Buy This Guest Post?

Before you hit “send” on that payment, run through this final checklist. If you answer “No” to any of the first 5, walk away.

Spam Score: Is it below 6%? (If no, RUN. 🚨)
Topical Relevance: Is the site 100% relevant to your niche? (If no, it’s a waste of money.)
Domain Age: Is the site at least 1 year old? (If no, too risky.)
Content Quality: Is their content well-written, edited, and valuable? (If no, your brand will suffer.)
Backlink Profile: Are their backlinks from reputable sources? (If no, they could be penalized soon.)
DA/DR: Is it within your target range? (Nice to have, but not a deal-breaker if relevance is high).
PA: Is the specific page strong? (Ensures your link isn’t on a dead page).

Trusted Resources & Further Reading

Google’s Guidelines on Link Schemes — The official word on what’s allowed.
Moz’s Guide to Domain Authority — Understand how DA is calculated.
Ahrefs’ Guide to Domain Rating — Learn the difference between DR and DA.
How to Find Guest Post Opportunities (The Smart Way) — Our step-by-step guide to finding quality sites.
Why Manual Guest Post Search Fails — The data behind why most people fail.

💡 Conclusion: Quality, Not Quantity, Wins in 2025

Buying guest posts is a high-risk, high-reward strategy. In the era of semantic search and E-E-A-T, the only links that matter are those that are contextually relevant, editorially earned, and placed on authoritative, trustworthy sites.

By rigorously checking these 7 metrics, you transform from a link buyer into a strategic partner, building genuine topical authority that Google rewards.

Remember, it’s better to have one link from a perfectly relevant, high-trust site than ten links from mediocre ones. Use this guide as your armor against bad actors and your roadmap to sustainable SEO growth.