People love photos. Photos originally weren't that big a part of the idea for Facebook, but we just found that people really like them, so we built out this functionality.

I think what we've found is that when you can use products with your friends and your family and the people you care about, they tend to be more engaging. I think that we're really going to see this huge shift where a lot of industry is and products are just going to be remade to be social.

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Mark Zuckerberg Quotes