A lot of people have been asking for a couple of years now "what is Twitter's revenue model?".
It appears they are now starting to show their cards. Twitter is introducing Twitter Pro. They will be offering paid accounts to businesses that use the microblogging platform for marketing, customer relations, publicity, and what-have-you. That's something Twitter has been hinting at for about a year now.
And this week it was announced that Yahoo and Twitter are forming a relationship. In the coming weeks Yahoo will be integrating Twitter into nearly all of its products and pages, including Yahoo Mail, Sports, News, Finance and Search.
Strength in numbers right?