There are NO ads, NO PPC advertising like Facebook, zilch.
Can you imagine having the 10th most visited website in the world and not knowing how to make money from it??? Am I the idiot here and missing something?
And on top of it... I can only imagine how much money they spend on bandwidth for all the traffic they receive and they also must pay mobile companies for SMS.
Seems to me like Twitter MEMBERS are making money from Twitter, but not Twitter themselves.
[ADDITION]: There is a large fundamental difference between SELLING a website and MONETIZING a website.
SELLING Twitter for billions of dollars is NOT monetizing the site... It's selling it to someone else.
If someone bought Twitter for billions of dollars... They would find themselves with a website that is NOT monetized. Catch my drift?