Seems like the only logical reason they are doing this is because they are in the start of an acquisition. They have to prove some type of revenue stream (ads) and restricting users to the twitter site/app will help them guarantee the made up numbers.
A different question is, who would want to buy them? Twitter, who should know their network better than everyone else, is still trying to figure out how to best monetize it. Who would want to take that task on?
In the old days, I'd guess Yahoo! would be in the running, but since they have a history of buying popular sites and then letting them wither, I hope Meyer isn't going to fall for that again.
I would be surprised but not totally shocked if either Microsoft or Apple bought Twitter. Tight integration into OS and devices + the huge critical mass of active social users + the social and cultural relevance of Twitter would be assets for them.
Facebook already has a social network. Google already has a social network. Apple's probably not interested in running one post-Ping. Who else is going to purchase them at a price their investors - who've sunk over a billion in VC $ - wouldn't balk at?
Have they really had over a billion in investment capital? I realize they may have had investment rounds valuing the company at 1bil+, that doesn't mean they were given a billion dollars.
