Advertising games seems to be hard for some reason: there are a lot of MMORPGs that basically parrot how they are free and they have this and that other "system".
Ever started playing Flyff (fly for fun) only to find out you can only really fly after you spend a good part of your week getting to some two digit level? Ironically, in Second Life, where the ability to fly isn't really advertised as a distinctive feature, we can learn how to fly (with pretty much no restrictions) within the first 15 minutes.
When it comes to targetting non-hardcore gamers, I like the concepts in Nexon (of Maplestory fame) ads: invitational tone using words most people can relate to. Who really cares about a "revolutionary party system" and "real PVP"?
Imo, unless you spend your weekends exhaustively trying every single new open beta MMORPG in the net, ads that invite you to "explore" and "chat" sound a lot more attractive than ads that seem desperate to set themselves apart from their competition by claiming to have features that only some hardcore gamers would be interested in.
Advertising campaigns for some other types of games just look plain awkward. If someone's not interested in Madden, I doubt a website with fabricated tips is going to get them interested. "Cutest quarterback"? Come on, whose friend do they think they are?
A nice quote from Scoble from way back in 2006: the next web is the human web. I think that advertisers could use a bit of that "humanization" too.