[benologist]

Facebook games are also declining, from Zynga at their peak to collectively less revenue than Candy Crush Saga on iOS.

http://www.businessinsider.com/facebook-payments-revenue-dec...

[soccerdave]

While it has declined, it is still almost a billion dollar industry on its own just on Facebook. You asked for "examples of games making heaps of money" and I included links to a bunch of them.