Why doesn't anyone play Nazi Zombies on PC co-op?

[Mitch]

It's such a great game and it seems really popular on the 360, but most of the time there is absolutely NO ONE playing online. Anyone know what's up?

Edit: Actually it seems like no one plays co-op at all...

[Ojnod]

On the PC is it kinda a hassle because you can't just go from playing regular MP to quickly check to see if any zombie games are up. I've only played it a handful of times with friends but I would imagine that this is the problem for most people.