The barrier to entry for an upstart is less than you might expect.
According to multiple lines of argument, the value of a network for users scales like O(n log(n)) where n is the number of users. The log(n) factor is sufficiently small that a new and better platform can get traction if the user experience on the most popular one degrades enough.
Now this has actually been happening, but Facebook has learned from what happened to Friendster and then MySpace and has been buying up potential competitors such as Instagram and Whatsapp. However it is just a question of time until a successful competitor doesn't sell..then manages to take Facebook's crown from it.
This probably won't happen within 5 years. I'd give it even odds in 10. But I wouldn't bet on Facebook remaining king for 20.
According to multiple lines of argument, the value of a network for users scales like O(n log(n)) where n is the number of users. The log(n) factor is sufficiently small that a new and better platform can get traction if the user experience on the most popular one degrades enough.
Now this has actually been happening, but Facebook has learned from what happened to Friendster and then MySpace and has been buying up potential competitors such as Instagram and Whatsapp. However it is just a question of time until a successful competitor doesn't sell..then manages to take Facebook's crown from it.
This probably won't happen within 5 years. I'd give it even odds in 10. But I wouldn't bet on Facebook remaining king for 20.
See http://www.dtc.umn.edu/~odlyzko/doc/metcalfe.pdf for some of the lines of evidence leading to that scaling conclusion.