For event organizers, the definition of failure is when counter-protesters and police outnumber your intended audience.
A good example to total event failure was the "Million Muslim March," which was just a bit shy of its goal...
by 999,975 people.
And it seems that the event wasn't so much about Islam, but about the
theories of 9-11 "Truthers".
Attendance evidently ran into the dozens, although it was hard to pick the demonstrators out from counter-demonstrators and reporters covering the event, who may have outnumbered them. It didn’t help that the event was linked to anti-Semites and 9/11 conspiracy theorist lunatics.
While the Biker's event was less than "2 Million", the turnout for these patriots was much more substantial.
Via Twitter and Twitchy, it looks like there were over 75,000 hogs on the roads of the nation's capital today.