sure twitter is allowed to be a success and i wouldnt call a 13B market cap medium sized. but in 2 years as a public company it's stock has only ended up below its ipo price, so pretty fair to say they've had trouble.

i agree twitter has introduced a form of communication that probably isnt going anywhere, but i dont really think it has a large cultural impact. aside from trump this election cycle i feel most 'famous' tweets are about as significant as here come dat boi.