Well, I have had the game since a couple weeks after launch, so my estimate of just taking the percentage of games I'd play a day and using that probably works out.
Do you think an average of 80 players online, 20 games going at one time is about accurate? We could figure out the number of days since the game's release and then calculate the total number of games played.
365 + 366 (2008 was a leap year) - 17 days (until Feb 4) = 714 days since release. At 240 games per day * 714 = 171,360 games played on ICO. If you had played 1000 games, you would have played in 0.584% of all games ever played.
I'm guessing that I've done about 1500 games total, so that puts me at 0.875%.
I think JJ would definitely hit the 1% mark.
What's kind of scary is that it's quite possible that 10% of all ICO activity can be accounted for by a handful of players, perhaps 15 people.