Comment by anovikov

Maybe it is failing to grow for the plain reason that it has already grew up, filling its niche? Why don't you question why BMW is 'failing to grow'? What's their mistake?

http://www.nada.com/b2b/Portals/0/assets/web-images/Luxury%2...

There is no mistake. There are only so many premium car buyers in the world.

By the IT measures, Twitter is a mature company. It does one thing and it does it well. It can't grow infinitely.