There's barely 1 billion people online worldwide. Granted, there are more than that who have mobile phones and could use Twitter via SMS, and the number of peo

There's barely 1 billion people online worldwide. Granted, there are more than that who have mobile phones and could use Twitter via SMS, and the number of people online by 2014 will probably be much higher (2 billion?), but they don't want 1 billion user accounts in their database, they want 1 billion active users who interact with Twitter at least once a week. Supposedly something like 80% of people who sign up for Twitter never return, so they'll need 5 billion signups to get 1 billion active users. Does Google even have 1 billion users who interact with them at least once a week?