OK – given that most of the spam referrals talk about "Online Poker", there seems to be a plot about to boost the Wikipedia page by Googlebombing so that those who Google search for things like "Play Online Poker" get the Wikipedia page on playing poker online instead.
Seeing as I get hit by this referral spam a lot, and nobody can see my referral logs anyway, I’m happy to contribute to this!
It seems to be working, the Wikipedia article is now number 3 when you search for poker online.