Could be. Another difference is how they came to success. Zuckerberg solved an "easy" problem building a social network web app whereas the Google founders solved a "hard" problem building search engine algorithms.
I was thinking about this on the way home. Regardless of what has become of Google they started off with "don't be evil", whereas Facebook has basically been "by any means necessary" from day 1.
The Winklevosses didn't do any work. They wanted someone to build them a dating site for Harvard students.
He was an asshole in their business relationship and should have stopped working with them the minute he was inspired to create Facebook. But he didn't steal anything that belonged to them. They would not have succeeded with their original idea even if they found a developer to do all the work for them.
The Winklevosses already had a substantial part of the project done, and it was more than a dating site. In fact, Zuckerberg copied the Winklevosses feature to connect people. In the absence of competition it seems likely that the Winklevosses product would have been successful. Zuckerberg admits they were well known on campus and would have promoted the site well. The key determining factor in the success of Facebook was not the quality of the software, or even its features, but that it was first social network introduced to the closed Harvard internal market.
