Runic Games didn't even want to release Torchlight 2 within the same year as Diablo III, but due to delays, the game was released about four month's after Blizzard's game.
That didn't seem to effect Torchlight 2 sales much, because according to Runic's twitter, "We had an amazing 2012, and proud to say that #Torchlight2 has sold over 1 million units! Thank you! Happy New Year's Eve everyone "
If you still havn't checked out the game, you can get it through Steam sale for only $ 15 until January 5.