The French and Russian revolutions both had multiple causes, economic, social and ideological. Although they were separated in time by over a century, they actually occurred in relatively similar internal developmental contexts, as Russia in the early twentieth century was still an agrarian economy led by a monarch, unlike western Europe which underwent the industrial revolution in the late eighteenth and nineteenth centuries.
In both countries, similar economic factors contributed to the revolutionary impulse. First, there was a dramatic degree of economic inequality. The was exacerbated by the way wealthy monarchs and nobles created extravagant displays of their wealth. Second, both countries were heavily indebted and their monarchs kept increasing taxation to sustain their own extravagant lifestyles. Third, both some of the French peasants and the Russian bourgeois were beginning to acquire some wealth engendering what Marx called a "revolution of rising expectations." Socially, the upper classes had many freedoms and acted with impunity while the lower classes were restricted from roles of power and a voice in running their country, breeding resentment.
In both cases, ideology played a role in the revolutions, but while the ideology behind the French one was Enlightenment liberalism, that behind the French one was Marxist, and valued the collective over the individual. Both revolutions were strongly anti-clerical and anti-religious. The Russian Revolution, though, was the more radical of the two, addressing gender and class in a more critical fashion.
Finally, in both revolutions, the original collectivism and ideological purity succumbed to the attractions of charismatic leaders, who used forces of propaganda and nationalism to create authoritarian states.