Suck My Trend - Christmas was big for Game Sales in 2012. Steam was a big part of that on the PC offering some brilliant deals every day on a variety of different games, even allowing members to vote on the game that they wanted to be reduced next, and the user favourite was the game that was discounted. Gamers loved this.
If we are talking strictly online downloads then the biggest point before Christmas will be when Dota 2 and that is just for concurrent players.