I signed into Yahoo! Mail today and discovered that it now offers 100 MB of space. That’s a pretty good upgrade from the 4 MB it offered up until now. I had to clean out my Inbox every three months or so. If I keep up that pace with, now, 25 times more space … I shouldn’t have to delete a message for the next six years!

It seems obvious that Yahoo! has made this free upgrade to its email service as a preemptive strike against Google’s Gmail, which will offer 1 GB of disk space. For free. Yahoo’s 100 MB isn’t as much, but it does make me think about MP3 players, where you probably don’t really need to carry every song you’ve ever heard.

But this is a big move on Yahoo’s part. I didn’t expect it. When Gmail goes final or into a public beta, I had planned on making it my primary email address for the disk space alone. Now, switching from Yahoo! Mail would mean telling everyone my new address, and that question pops up: Do I really need a gig for my email?