Question is, in the ~13 years since, was ICQ worth its $400m price? Is Twitter really worth x2.5 that?
The ICQ equivalent would be to have someone like starbucks open up a chat with users and still manage to somehow retain the users.
Certainly though I see this growing on Facebook to, I don't think there is only room for one game in town here though, so far companies have been happy to work across both platforms. Depends a lot on Twitters future user retention and engagement I guess.