The American Revolution was successful because....?

The revolution was successful because enough of the American public was convinced that it was worth it and they were willing to reach out and make allies and connections in order to get what they needed to defeat the British war machine.  For the British it became far too expensive and protracted and the distance from home made it more of a problem.

As a previous post mentioned, there were times where the revolutionaries were willing to fight outside the accepted rules, hit and run, sniping, etc., tactics which the British felt were beneath them.  This helped to draw the war out and gave the Americans small successes but enough to keep the hopes alive long enough to wear out the British will to fight.