Marketing Statistics Roundups Source 54% of Their Numbers. HubSpot's Blog Is Their #2 Source.

By Priya Raman, AI SEO, GEO & Martech Analytics. Last updated: 2026-08-16

"73% of B2B buyers say..." Every marketer has quoted a number like that from a roundup. We wanted to know how many of those numbers, on the roundups themselves, point anywhere.

How many numbers in marketing statistics roundups are sourced?

We harvested the sitemaps of the 54 martech vendors from our other research audits and 20 independent marketing publications, pulled every URL with "statistics" or "stats" in the slug, and fetched up to two per site. Then we filtered hard: a page counted only if its title was a genuine roundup ("27 Cold Email Statistics You Need to Know," "65 Marketing Statistics to Guide Your Strategy") and not a docs page, a first-party study, or a dated report. Thirty-two pages from 24 publishers survived, 26 vendor and 6 independent.

On each, every paragraph or list item containing a percentage, a multiplier, a dollar figure or a large number counted as one stat block. We then checked whether that block contained a link to a domain other than the publisher's own.

Just over half. For content whose entire value proposition is "here are the numbers," nearly half the numbers are asserted rather than attributed.

Which roundups source everything, and which source nothing?

The spread is enormous. Backlinko's "161 Incredible Digital Marketing Stats" sources 111 of 116 blocks. Qualified's B2B buyer statistics page sources 68 of 68. Braze's in-app monetisation stats, 20 of 20. Iterable's omni-channel stats, 30 of 31. AiSDR's sales statistics, 111 of 117. Writesonic's AI SEO statistics, 42 of 43. These pages are, in effect, annotated bibliographies with commentary, and they are the ones worth citing from.

At the other end, six pages link essentially nothing from their numbers. Cognism's "80+ Must-Know Email Marketing Statistics for 2026" has 61 stat blocks and zero inline sources; re-checking the whole page for a sources footer found three external hosts in total, LinkedIn, TikTok and its privacy vendor. Klaviyo's "778 online shopping stats" has 326 stat blocks on the page we fetched and links to one research host anywhere on it. Regie.ai's lead-generation statistics, 33 blocks, one external host (LinkedIn). Surfer's B2B marketing stats, 12 blocks, review-site links only. Two Marketing Week "5 interesting stats" columns cite in prose without links, which is a newsroom convention rather than an omission, and we note it as such.

One exception worth naming: Typeface's content-marketing statistics page fell outside our title filter, but when checked it carries 18 external source hosts in a footer rather than inline. It is why this study measures inline sourcing specifically and says so.

Where do the citations point?

This is the part that surprised us. Across the 32 pages, the domains cited most often are:

Statista, an aggregator, leads. HubSpot's blog, itself a publisher of statistics roundups, is second. Of the thirty most-cited hosts, we classified fifteen as other vendors' or marketing blogs (HubSpot, Invesp, OptinMonster, Campaign Monitor, Yesware, Mailchimp, GetResponse, Gong, InsideSales, RAIN, MarketingSherpa, CMI and others), ten as research or primary-ish sources (Statista, Gartner, Pew, McKinsey, eMarketer, LinkedIn's business research, Salesforce's State of Sales, Think with Google, PR Newswire, Forbes), and five as other.

A roundup citing a roundup is not a citation. It is a pointer to a pointer, and somewhere down the chain there is either a real survey or nothing. Our own editorial rule, applied to every stat we publish, is to trace the chain to the study or drop the number, and the AI Until I Die team's audit of where viral AI-failure statistics actually come from found the same circularity in a different corpus.

Why does inline sourcing matter more than a footer?

Two reasons. A human reader checks the sentence they are about to quote, not the bottom of a 3,000-word page. And an answer engine extracting the claim "73% of B2B buyers prefer..." takes the sentence and, if a link is in it, the source; if the source is forty paragraphs away in a "References" block, the claim travels alone. Our guide to structuring content so AI engines quote it treats the sentence-plus-citation as the unit for exactly this reason, and it is why GTMStack's own posts put the link where the number is.

The 54% figure is therefore also a citability figure, and it is the reason we track whether AI engines cite us at the sentence level rather than the page level. Half of the numbers in the industry's statistics content are extractable with provenance; half are extractable without it, and those are the ones that become "studies show" in someone else's deck.

What are the limits of this audit?

Up to two roundups per site by URL pattern, filtered by title, so 32 pages is a sample. A "stat block" is a paragraph or list item containing a number pattern; some are not statistics (a price, a year, a step count) and some statistics are phrased without a number pattern, so the 1,756 is approximate in both directions. "Inline" means the same <p> or <li>; a source link in the next sentence, in a separate paragraph, or in a footer does not count, and we flagged Typeface as the case where that rule bites. Host classification into blog versus research is a judgment call recorded host by host in the data file. Snapshot of 2026-08-16.

FAQ

What share of marketing statistics roundups link a source for each number?

In this audit of 32 roundups, 948 of 1,756 numbered claims (54%) had an outbound source link in the same paragraph or list item.

Which marketing statistics pages have no inline sources?

Six of 32: Cognism's email marketing statistics, Klaviyo's 778 online shopping stats, Regie.ai's lead generation statistics, Surfer's B2B marketing stats, and two Marketing Week stats columns that cite in prose without links.

What sources do marketing statistics roundups cite most?

Statista (13 of 32 pages), HubSpot's blog (10), hubspot.com (7), LinkedIn's business research (6) and salesforce.com (6). Of the 30 most-cited hosts, 15 are other marketing blogs.

Which roundups are the best sourced?

Backlinko (111 of 116 claims sourced inline), Qualified (68 of 68 and 156 of 173 on two pages), Braze (20 of 20), Iterable (30 of 31), AiSDR (111 of 117) and Writesonic (42 of 43).

Why does it matter whether the source is inline or in a footer?

Readers and answer engines extract the sentence containing the number; a source in the same sentence travels with the claim, while a footer reference does not.

Sources

• Backlinko: 161 Incredible Digital Marketing Stats
• Cognism: 80+ Must-Know Email Marketing Statistics for 2026
• Klaviyo: 778 online shopping stats
• AI Until I Die: Which AI failure stat is true?
• Statista

GTMStack publishes original audits of the AI marketing stack. If you want the next one when it lands, the newsletter is the place to get it.