Seeing the comments below., the similar questions could be raised for a even bigger bandwidth beast. Youtube. And imgur is essentially the Youtube of images.

And speaking of profits, 140 Characters is barely generating any revenue despite it would be the only service of its size consuming the least (hosting) resources.

So I guess investors do not see the value in profits rather in popularity when it comes to crazy start-ups. Considering Instagram which got acquired for the ‘notorious’ 1 Billion. If we use the same mathematical formula, I guess imgur is worth at least 2x of Instagram.