Here's my stab (probably about as accurate as any of the misleading answers on quora):<p>0: realizing that search was important on its own (it wasn't a loss leader or a gimmick to get people to visit your portal where the real content and money making happened)<p>1: using cutting edge research to improve search result quality based on human factors (page rank)<p>2: using cutting edge computer science to create highly efficient search systems through sharding and aggressive parallelization.<p>3: facilitating aggressive parallelization through highly automated data center operations relying on large quantities of consumer grade hardware.<p>4: continuing concentration on human factors (UI simplicity, search result speed, unobtrusive advertisements, etc.)<p>All of these together made google a juggernaut, with some of them google would have been successful but maybe not dominant, with all of them nobody could touch google so long as they managed to monetize well. Better search results faster at lower cost per query and with much higher click-through rates for ads. That's a world beating formula right there.