Far more often than not, even bloody revolutions do not achieve their goals, or lead to merely cosmetic and/ or short-lived changes. E.g. Kent Gang Deng investigated 269 major peasant rebellions over 2106 years of Chinese history. Guess how many of these actually rewrote history in any way, shape or form.
Recently, I've been reading several interesting pieces on the "Occupy" movement, the related G20 and other protests in the Western world, dating back as far as the 1960s. The bottom line being: asking nicely for some minimum demands that even conservative politicians can get behind, like capping CEOs' wages, will not get the job done. In fact, some of the powers that be can use it for their internal power struggles and to show it off as a sort of legitimization folklore. "See how democratic we are? We even have protesters in little tents! Don't worry, they aren't hurting anyone."
All hope is not lost, though, if new protest modalities can be found.