Ask a developer how they evaluate a new API or SDK and almost none of them mention the marketing site. They open the docs. Specifically, they open the quickstart, they check whether a code sample actually runs when pasted in, and they look for what happens when something goes wrong - the error messages, the rate-limit behavior, the edge cases the happy-path tutorial doesn’t cover. That whole evaluation happens without a single sales conversation, and for a large share of technical buyers, without ever loading the homepage at all.
Which means the documentation is not adjacent to the pitch. For this buyer, it is the pitch, and most companies staff and budget it like a support cost instead.
The tell is in who owns it
At companies where docs read like an afterthought, they usually are one: written by whichever engineer shipped the feature, published without a review pass, and never revisited until a support ticket forces an update. At companies where docs read like a product, someone owns them the way another team owns onboarding flow or pricing page copy - with an eye for what a first-time reader doesn’t know yet, not just what’s technically true.
The difference shows up in small things a developer notices without necessarily being able to name what tipped them off: does the first code sample actually work if you copy-paste it, or does it silently assume three setup steps that live somewhere else? Are error responses documented, or do you find out what a 429 looks like by triggering one yourself? Is there a changelog you can trust, or do breaking changes get discovered in production?
Trust is transferred before a single sales call happens
A technical buyer who has a good first experience in the docs arrives at any eventual sales conversation already halfway sold, and openly skeptical of anything that contradicts what they already found true by testing it themselves. A buyer who hits confusing docs arrives, if they arrive at all, defensive - primed to assume the product has the same rough edges as the documentation describing it.
This is why the best developer-tool companies treat their docs site with the same design discipline as their marketing site, sometimes more: consistent terminology across every page, runnable examples kept in sync with the actual API through automated testing, and a search that returns the right page on the first try. None of that is generosity. It is the recognition that for this specific buyer, the documentation is doing the job a sales deck does for everyone else - and unlike a sales deck, nobody is in the room to explain away its gaps.