Actually, Basecamp has this in large text on the homepage: "Last week 6,033 companies signed up for Basecamp to manage their projects. Today it’s your turn."

Actually, Basecamp has this in large text on the homepage: "Last week 6,033 companies signed up for Basecamp to manage their projects. Today it’s your turn." It's clear that Basecamp is some sort of tool to manage projects. A project management tool. An about link is okay but it should be obvious as soon as you land on the homepage, or any landing page, what the product does. Basecamp actually clearly describes what it does as soon as you hit the homepage.