"Free unlimited storage" is being introduced for Yahoo Mail users this month. It's one of the first cases of Internet boundlessness, where the resources of the Web have become so vast that normal measurements don't matter any more. At least that's the theory. In reality, there are limits to Yahoo's limitlessness. Still, competitors are taking note. Microsoft, for example, which runs Hotmail, says it will move to "take storage off the table as an issue."
Yahoo and Microsoft's Hotmail each have around a 40% penetration of the global Web-based email market, says ComScore, with Yahoo slightly ahead. Gmail, while a darling of the tech set, is a distant third at around 11%, though its 62% growth rate from last year made it the service that's coming on the fastest.