He used the tools in the right way, and it was no small feat that should be dismissed that easily. Just a quick summary:

1) Give consumers what they want instead of what you think they want.

2) He used tools as intended. Instead of wasting time implementing Erlang trying to achieve the best messaging platform ever, he went with something that was popular and was easy to understand for everybody at the time, which was PHP. Then went on to improve the system as they needed with HHVM, React, React Native, etc.

3) As much as somebody can hate Facebook for being a social network/privacy leech, which is something a lot of programmers dismiss precisely because of the social part, just the fact they popularized React as one of the defacto front-end frameworks speaks volumes about how they can push real innovation for everybody else.

4) And even simple stuff like sharing pictures. I still remember vividly how awkward was to share pictures before Facebook. Sure, I think Flickr or similar stuff was there already, but nobody is going to keep clicking on your gallery so they can see how an amazing photographer you are. Sometimes the greatest innovation is in the simplest things, and if you ask me, this was THE feature they brought to the table.

Yawn. mixi.jp was doing Facebook before Facebook was widely available. It even had the much-vaunted news wall. Mixi screwed themselves in a few ways, mainly by being a Japanese-only site and (later) requiring a Japanese phone number to register, but still, Facebook was hardly an innovation. Mixi was written in Perl. (In fact Mixi has/had features which even now I've never seen in social media sites, such as the "ashiato" feature where you can see who has been looking at your profile)

I don't think seeing who looked at your profile is a hard feature to build. Odnoklassniki (russian social website) has it.

It's obviously a conscious business decision.

LinkedIn, any number of dating sites, and I believe MySpace all have (had) it.

When a site is focused on "social", like MySpace or Facebook, it comes across as invasive. When a site is focused on personal "marketing", like LinkedIn or dating networks, it can more be useful feedback on your reach.

EDIT: I hate the word "creepy"

So you are saying that the Wright brothers did not innovate because Alberto Santos Dumont among others did the first experiments regarding aviation (or heavy aviation as they say)?

This is the first time in my life that I have heard about mixi.jp. Facebook was able to capture not only the US but almost the whole world for that matter. Again, dismissing those achievements as if they were nothing really does not give them proper credit.