I bet he makes a fair few quid; But I also think he could make a lot of cash by selling the data of it's members to research companies, like Facebook do.
Just think. This site has a fairly large user base at 50,000 members, a large sample size could be taken from that. We all supply the necessary information that researchers would require (what games we own, how old we are, where we live). You could offer research companies valuable information about their target consumer.
For example; If a company wants to know what genre is most popular with gamers age 21-30 in Britain, it would be much more simple and cost effective for them to buy the information directly from ioi, as opposed to go out and do expensive and time consuming field research.
In fact ioi, I think you should do this if you don't already.