"Living on Virtual Fish" by Tim Howgego (firstname.lastname@example.org)
Talking about the revenue surrounding websites on World of Warcraft. Millions of dollars of affiliate advertising revenue.
Don't apologise for having advertising on a site. Adverts that are most successful are those that look most like the site content (is this tricking users?). Better to have ads down the side rather than at the header.
Most affiliate sites only pay out when you reach $100 so best not to go for too many different affiliates. Vary advertising though for repeat visits. Not sustainable, as the MPOG won't go on for long.
Nothing physical in the chain as buying knowledge to use in an online game. Similar to buying virtual gifts in Hot or Not or Facebook.