doesn't really apply to startups. Yahoo is huge and mainstream, they HAVE to support every browser, they can't present a crappy looking site to 5% of their user

doesn't really apply to startups. Yahoo is huge and mainstream, they HAVE to support every browser, they can't present a crappy looking site to 5% of their users. That 5% means millions of users getting a crappy experience, and possibly going elsewhere. On the other hand, startups can afford to show a "crappy looking" version of the site since its more or less expected. + the % of IE6 users is much smaller for startups, since startups typically have early adopter users.