Some interesting lines from the
GMail FAQ:
How much does Gmail cost?
Gmail is a free service and includes
1,000 megabytes of storage with each account.
What about spam?
Gmail includes a sophisticated spam filter that we're continuing to improve.
Are there ads in Gmail?
There are no pop-ups or untargeted banner ads in Gmail.
Sounds cool, doesn't it? So why don't I get a GMail account?
"because Gmail includes 1,000 megabytes of storage, a typical user won't ever have to worry about deleting mail."
This is why. Thanks, I don't want my emails to get indexed.