I'll provide a few comparisons; this is an interesting question that deserves a book length treatment. My apologies if in my attempt to be brief I oversimplify either side.
The American revolution occurred at the beginning of the British imperial age; the first Indian rebellion occurred during the height of Imperial power. The American revolution occurred during a time when the English constitution was undergoing significant reform; the first Indian revolution took place when the English consitution was fixed. Without getting too Whigish, the American revolution was driven by the desire to guarantee English rights to Englishmen living in English territory, and so enjoyed significant popular support even within the mother country. ("independence" was an accidental outcome desired by neither side). India sought rights which were somewhat alien to the English domestic population. John Bull could sympathize with the notion that an Englishman shouldn't be taxed without representation; it was more difficult to persuade John Bull that enlisted men should be protected against beef tallow. The American revolution had a relatively coherent ideology; the Indian revolution as wikipedia states, failed to provide a corresponding ideology. Probably the most important factor was that the United States relied on the assistance of France, while India had no similar external ally.
Update: @Lohoris asks about the native populations. Both countries had native populations. The British policy in America was to displace the native population and settle the territory as English territory. (Jack Rakove's lectures are indispensible to understanding this), while India was more densely populated and the British policy centered on economic exploitation rather than full displacement and incorporation. I think the British strategy in India was in part derived from the results of the American revolution, which is one of several reasons I chose not to address it. I think the role of the British relationship to the native population is complex and nuanced, and I know that I'm not qualified to address that question, and I'd be very skeptical of anyone who tried to deal with that question in an essay the length of a SE post.
I'd love someone to analyze the diversity of the rebelling populations, the role of the Company, and other factors.