How we count

Installmap crawls four company lists as sets: the Inc 5000, Y Combinator companies, the Fortune 500 and unicorns. Every share on a group page uses the domains in this table as its base.

A domain enters the denominator when a fetch returned a page we could score. The rest are dead domains, parked pages and blocks we did not get past.

Each homepage is loaded in a headless browser. When the render fails, a plain HTTP fetch stands in: 72 Inc 5000 domains and 144 Y Combinator domains were counted that way.

On the domains where both fetches worked we compared the two. Across 3,569 Inc 5000 domains, a plain fetch found 36.7% of the installs the rendered fetch found. Across 5,095 Y Combinator domains it found 45.6%. Most analytics and ad tags are injected by JavaScript, so a plain crawl undercounts them badly.

The homepage is also a limit on what can be counted at all. Payment processors usually appear at checkout, email marketing runs from a sending domain, and server-side tools leave nothing in the page. A tool like that is missing from these counts even when the company uses it.