Obligatory reference to Betteridge's Law of Headlines[1]

    Any headline which ends in a question mark can be  
    answered by the word 'no'

AirBnB & Twitter each had three founders. VMWare had five founders[2], and they've done alright.

[1] http://en.wikipedia.org/wiki/Betteridges_Law_of_Headlines

[2] http://www.quora.com/Startups/Can-a-startup-be-successful-wi...