You've got Gmail!

Gmail is the fastest-growing online e-mail offering in an increasingly competitive market.

If you use online e-mail programs, chances are you've added Google's free Gmail to the mix. Since leaving "by invitation only" status in early 2007, Gmail has seen its usage rise 47%. It's the fastest-growing online e-mail offering.

Microsoft and Yahoo dominate webmail. They're virtually tied for the top spot. In February, the most recent statistics available, they had 256.2 million and 254.6 million users, respectively, according to researcher ComScore Media Metrix.

Google is No. 3, with 91.6 million users. No. 4 AOL, the company that first popularized Internet mail in the 1990s, has 48.9 million.