Scaling a product like that is an incredible engineering achievement, but I am speaking specifically about product development. What other products has Facebook innovated internally, worked through the product-market fit, and scaled itself? Again, my point is that they have a ton of resources and a huge existing user base, but the only successes they seem to have are purchasing companies that are ramping. They deploy engineers and connect to the existing user base, but they aren't innovative in product design.
facebook itself is a myspace or nexopia clone
the targetting pixel and like button are the most obvious innovations?
facebook is a tool for building products on, rather than a product in and of itself.