After recent years' spontaneous uprisings in e.g. Tunisia, Egypt, Syria, Bahrein, Georgia and Ukraine (twice), and with an outlook towards the revolutions in Western Europe in 1848, one should be able to establish a General Rule. Namely:

This is in no way peculiar. That the revolt is unprepared and spontaneous is in itself a sign that there is not much democratic organization in the country. There is thus not much political basis for a government to pursue a radically different policy than what the government has done that people have turned against. New governments will therefore cater to roughly the same organized power groups as the previous ones—business, the military—and pursue roughly the same policies, whether they want to or not.

On the other hand, a spontaneous revolt may very well succeed quite well if it makes well-defined demands for measures. All the so-called IMF revolts at the end of the 20th century did this. They erupted in the slums of indebted countries in response to austerity measures imposed by their governments at the behest of the IMF and to repay their loans. The revolts usually led to the withdrawal of the worst austerity proposals.

What they also led to was better political organization among the majority of the population. The countries that had the largest number of IMF revolts, Argentina, Bolivia and Ecuador, have since then had governments whose policies differ somewhat from the old oligarchic regimes, in favor of the majority.