No Fortune 500 homepage identifies visitors by name. 5.7% of YC homepages do

Key findings

1. No Fortune 500 homepage runs a person-level visitor identifier: 0 of 472 (0.0%). On Y Combinator homepages 306 of 5,386 do (5.7%).
2. Any visitor-identification vendor at all is on 16.5% of unicorn homepages, 15.9% of the Inc 5000, 12.1% of YC and 6.4% of the Fortune 500.
3. The leader flips by group. ZoomInfo WebSights leads the Inc 5000 and the unicorns, Apollo.io Tracker leads YC, and Demandbase leads the Fortune 500.
4. 38.2% of unicorn taggers run two or more vendors at once (63 of 165), the highest of the four groups.
5. Salesforce is one of the 30 Fortune 500 companies with a tag, and it runs Demandbase, not its own product.
6. 84.6% of YC person-level taggers have no consent-management tool detected on the same homepage (259 of 306), against 38.2% of unicorn ones (13 of 34).
7. Inc 5000 industries split by more than fifteen to one: 34.4% of the artificial intelligence and data companies run a tag and 2.2% of the legal ones do.

We went in expecting the Fortune 500 to be the heavy users, because account-based marketing is sold to large enterprises and those are the companies with the budget for it. The any-vendor share says the opposite: the Fortune 500 is last of the four groups. The person-level tools, the ones that put a name and an email on an anonymous visitor, do not appear on a single Fortune 500 homepage we scored, and they are most common on the startup lists.

No Fortune 500 homepage identifies visitors by name. 5.7% of YC homepages do

Person-level means the script resolves the visitor to an individual's name and email address. Company-level means it resolves the visitor's IP address to a company and stops there. Seven of the vendors we fingerprint are person level: RB2B, Warmly, Vector, Retention.com, Customers.ai, Opensend and Hyros. The other nineteen are company level.

0.0% of the 472 Fortune 500 homepages we scored carry a person-level identifier, and 5.7% of the 5,386 YC homepages do, 306 domains. Source: Installmap, September 2026. The 30 Fortune 500 companies that run anything at all run company-level tools only. On the Inc 5000 the person-level share is 4.5% and on the unicorn list it is 3.4%.

A domain can carry both kinds at once, so the person-level and company-level rows add up to more than the any-vendor row in every group.

16.5% of unicorn homepages run a visitor-ID vendor and 6.4% of the Fortune 500 do

The unicorn list is the top of the any-vendor table at 16.5%, the Inc 5000 is next at 15.9%, YC is at 12.1% and the Fortune 500 is last at 6.4%. The gap between the highest and the lowest group is ten percentage points.

ZoomInfo leads the Inc 5000 and the unicorns, Apollo leads YC, Demandbase leads the Fortune 500

Inc 5000 (n=4,885)

ZoomInfo WebSights is on 6.57% of Inc 5000 homepages, more than twice the Apollo.io Tracker share of 2.82%. RB2B is third at 2.40% and is the first person-level vendor in the table. 68.0% of this group's tagger domains carry at least one of the top three vendors, 529 of 778.

Y Combinator (n=5,386)

Apollo.io Tracker leads YC at 3.19%, and Apollo's tracker ships with its free plan, so a YC company can end up with one installed without buying anything. RB2B is second at 2.86% and Vector third at 2.28%, both person level. ZoomInfo WebSights, the leader on two other lists, is fourth here at 1.36%. 59.1% of this group's tagger domains carry at least one of the top three vendors, 386 of 653.

Fortune 500 (n=472)

Demandbase is on 11 Fortune 500 homepages and ZoomInfo WebSights on 10. Only eight vendors appear on this list at all, and 80.0% of this group's tagger domains carry at least one of the top three vendors, Demandbase, ZoomInfo WebSights and 6sense, 24 of 30.

Unicorns (n=1,000)

ZoomInfo WebSights is on 7.10% of unicorn homepages, its best group of the four, and 6sense is second at 5.10%. 70.3% of this group's tagger domains carry at least one of the top three vendors, ZoomInfo WebSights, 6sense and Demandbase, 116 of 165.

Retention.com owns RB2B and the two share a script family, so a site running the Retention.com pixel can score as RB2B. Both are person level, so the person-level totals hold, but the split between those two rows is not exact.

38.2% of unicorn taggers run two or more vendors

Stacking is normal once a company installs anything: 38.2% of unicorn taggers run at least two vendors, and even on the Fortune 500, where only 30 companies have a tag, 20.0% of those run more than one.

All 30 Fortune 500 taggers run company-level tools

Salesforce, at rank 114, runs Demandbase on salesforce.com. The list skews to technology, energy and business services. Five of the 30 rank inside the top 100: Dell Technologies, Lockheed Martin, International Business Machines, Ingram Micro Holding and Travelers.

34.4% of Inc 5000 AI and data companies run a tag and 2.2% of the legal ones do

The top five industries are artificial intelligence and data at 34.4%, software at 32.3%, security at 30.5%, human resources at 27.1% and IT services at 27.0%. The bottom five are government services at 4.4%, construction at 4.3%, aerospace and aviation at 4.2%, consumer services at 4.0% and legal at 2.2%. Advertising, marketing and PR is the outlier: its any-vendor share of 22.6% puts it eighth, but its person-level share of 9.3% is third, so the agencies that install anything reach for the person-level tools more often than their overall rank suggests. The last five rows have a base under 20 crawled domains, so we print n/a rather than a share for them.

YC batch years peak at 20.9% in 2023

The 2005 and 2006 rows have a base under 20 and print n/a, as does the single 2027 company. Excluding the two incomplete years, the peak is the 2023 batches at 20.9% any vendor and 11.3% person level.

The 2025 and 2026 rows are marked incomplete for a reason. We crawled those companies soon after their batch, and a young site has usually not installed a tag yet, so their low shares are a function of when we looked rather than a decline in the category. Do not read the last two rows as a trend.

84.6% of YC person-level taggers have no consent-management tool detected

84.6% of the YC companies running a person-level identifier have no consent-management tool detected on the same homepage, and on the Inc 5000 that figure is 78.6%. Unicorns run the other way at 38.2%. Across all taggers, not only the person-level ones, the Fortune 500 is the group most likely to have a consent tool: 26.7% of its taggers have none, against 81.2% of YC's.

Two things keep this a floor rather than a count of violations. A hand-built banner leaves no vendor fingerprint, so a site can show a banner and still score as no consent-management tool detected. And a script that a consent tool holds back until the visitor agrees does not fire in our render, so we undercount installs on exactly the sites that gate them. Both errors push the same way, so the true shares are higher than these.

Data funnel

A domain drops out when no fetch returned a page we could score: the domain was dead, the page was parked, or the site blocked us. The outputs count the drops without recording a reason for each one, so we do not print a split of the dropped rows.

Method

Nothing was crawled for this post. The rendered homepage archive was already on disk, we added fifteen vendor fingerprints to the visitor-identification category, and we rescored all four groups from the archive on 2026-09-15. Each rule was written only after finding the vendor's own hostname in the archive with a grep over the stored HTML.

The rules are narrow on purpose. Bombora, Influ2, KickFire and Retention.com turn up on many homepages as a name in a consent banner's provider list, an entry in a Content-Security-Policy header or an opt-out link, and none of those is an install. We checked by hand that glean.co, catonetworks.com, competera.ai, bny.com, morganstanley.com, burrow.com and adaptional.com all score zero.

Limitations:

• We see the homepage and nothing else. A tag that only loads on a pricing page, behind a login or at checkout is invisible to us, so every share is a floor.
• Every number comes from a rendered fetch, because these tags are injected by JavaScript. A plain fetch finds only part of them. Where no rendered record was usable we fall back to the plain record, which is 72 Inc 5000 domains and 144 YC domains.
• The Fortune 500 rows are filtered to the 2026 list. The 2023 list is held separately and is not counted here.
• We do not publish a share on a base under 20 crawled domains, and a count of one to four prints as "<5".

To check the ZoomInfo count against a public figure we read ZoomInfo's own number. Its about page at https://www.zoominfo.com/about says "Join 30,000+ customers growing with ZoomInfo". We find ZoomInfo WebSights on 475 domains across the 11,743 we counted. That is the shape we expect: WebSights is one feature of the platform, only some customers put the tag on their homepage, and most ZoomInfo customers are not on any of these four lists. BuiltWith's public counts would have been the other check, but trends.builtwith.com returned an HTTP 202 challenge page through our proxy.

Dataset

Everything behind the tables is published under /static/data/visitor-identification-tags/: by_group.csv with the vendor counts and shares per group, domains.csv with one row per tagged domain including the person-level and consent-tool flags, inc_by_industry.csv, yc_by_year.csv, fortune500_taggers.csv, a README.md listing the columns and denominators and a METHOD.md covering the scoring date, the level definitions, the consent flag and the suppression floors. Data: CC BY 4.0, Installmap, 2026-09-15. Next to any number here, cite: Source: Installmap, September 2026.