I believe Microsoft is paying you. they are paying you because they are trying to drive users to the live.com search feature. They are paying you that much because eBay is probably giving them money to advertise their business on live.com. (Notice how it's only on BIN/PP items, and if I'm not mistaken, FVF on BIN just went up).
So eBay is giving some sort of kickback to MicroSoft. All that matters is you get paid, right?