In my opinion, it was a combination of how willing Facebook was to accept change - and how unwilling MySpace was.
How MySpace lost out to Facebook
When I was a teenager, MySpace was HUGE. My social networks of choice were MySpace, LiveJournal and something called Faceparty!
But of the three platforms, MySpace was by far the biggest. Everyone was using it, and it was a joy to use too.
I have fond memories of customizing my background or adding tracks to my profile...
The downfall of MySpace came about when they were bought out by Rupert Murdoch's NewsCorp.
You'd think having the investment and know-how of the world's biggest media and publishing corporation would have seen MySpace's market share skyrocket.
Instead, it slipped quietly into the social media abyss, and Facebook rose to become the world's largest social network.
My theory is pretty simple: Facebook listened to their users, moved with the market, and weren't afraid to innovate.
MySpace did the opposite.
When NewsCorp execs took over MySpace, they had a plan. They hired the best people in the business, invested a lot of capital, and developed a strategy they thought would work. And they stuck to that strategy even when the market made it clear it wasn't happy.
Facebook, on the other hand, started off as a much smaller beast. Rather than beginning with ambitions for world domination, Facebook moved with it's user's demands - it followed the market demand and wasn't afraid to make changes and keep changing, as long as the growth was there to justify it.
If people wanted Farmville-style games, they could have them. If people moved en-masse against a certain feature, it would disappear.
Facebook weren't afraid to make mistakes - but their goal was growth, and they didn't pretend they knew how to get it. Instead, they listened to what their users wanted, and they kept trying new things out.
Even to this day, it seems like Facebook is constantly rolling out a new feature or a big overhaul.
And their company culture reflects that.
They don't prejudge or second-guess what users want, they just keep going with whatever people ask for so long as they keep growing.