I noticed today that twitter is creating an enormous amount of micro-content. Check this page. I don't see any reason why they couldn't ad some advertising to this micro-content later. All of this could be indexed by Google and generate a large number of referrers. Not the greatest business model, but could work.
http://twitter.com/kentnewsome/statuses/25289191
BTW, I finally got some SMS from Twitter. Unfortunately they were 24 hours delayed. The SMS that I shoulda received yesterday arrived today.
And of course, Kent Newsome is having trouble w/ LiveWriter to Blogger.
Update: Someone replied to this comment with a private email saying "the reason your sms was delayed is probably your network provider's (a.k.a., phone company) gift to you..." But I get SMSes all the time and they usually arrive immediately.