I can't say for sure, but I CAN say that games (modern warfare 2, in my case) are sapping my productivity. I've put almost 300 hours into that goddam game, and I still enjoy playing it. Those are 300 hours I could have been working
If I was going to buy porn, I doubt it social networking or games or whatever would have an effect on my purchasing habits... Everyone likes to smash their cock around while they watch porn, and will always find time for it.