 :::Um, quick answer, no.  We have an arrangement, I think, but I see where you are going.  Um, I'm one of those people who ignores the answers tie up, so I'm not sure what it is. I think they re-use our content per the GFDL, but there's a donation which comes the other way in exchange.  There's politics involved, to avoid advertising which many people feel Wikipedia shouldn't do.  I never made my mind up on that, to be honest.   