I guess our slight disagreement is because I'm stuck on the idea of 'social game' needing more than 2. Like 2 guys by themselves playing cards against doesn't seem social (to me... I'm sure by any dictionary's definition, 2 people getting together to have fun is 'social').
But 2 guys playing cards at the local pool hall surrounded by people (some of whom they know) sounds a lot more social
Anyway, it's certainly fair to say cards are cheaper and you can get more than 2 playing, so I can accept pool isn't the #1 cheapest social game. But it my hands-down favorite inexpensive social game, and I definitely know more pool players than cards players if I'm bored on a saturday night.
The other thing about pool being social is that while two people may be playing a pool match, there may be several people watching. Pool is also unique in that you may be as social as you like. In fact, when there is a big match going on many people congregate to sweat. I don't think when two people are playing a game of hearts, a big crowd is going to sweat their game.
But each person has their own preference. Book like cards. No problem. I like pool and yes I find it more social than playing cards, although I do some of that as well. Card playing between two people is fairly popular here in the South at many pool rooms but you seldom see anyone sweat a spade game for more than a few minutes.
I've even seen people sweat pool matches for eight hours at a stretch. Ive never seen anyone sweat a card match for more than 30 minutes.
JoeyA
LOL I would bet dollars to donuts that the average poolplayer doesn't spend 400 hours a year playing pool. 
