I think a "thank you" at least would be appropriate.

I don't think I'd jump straight to payment for referrals - it could lead to an expectation.

Send 'em 2 "box-o-coffee"s, two dozen assorted donuts, a box of bagels, a thing of cream cheese, and a dozen assorted muffins just before start time - that way, everybody should find something they like, and a "thanks for the referrals" note will let them know why.

ETA - and a "box" of hot chocolate, for the non-coffee drinkers [Linked Image]

[This message has been edited by DougW (edited 11-02-2005).]