[colonel_panic]

One Intrade commenter from London claimed he was set up to earn about $20,000 in arbitrage against Betfair. If you expect the manipulation to continue over a period of time (which I certainly did, and wished I could register on other betting sites), it's worth it to deposit larger sums of money with bank transfers despite the wait.

At one point I wondered whether the manipulators were making large purchases once per day and whether this could explain why the different betting sites never came back in line with each other. In that case, a savvy arbitrageur might take advantage of prices while they're at their widest differential, and then wait to buy more the next day. I thought I saw a pattern like this going for a few days in a row but it was gone by the time I felt confident enough to trade around it.