I noticed on UltimateBet once as to where it was a $25+$2.5 with a Guaranteed Prize pool of $2,000. I was too late, but there were only 8 ppl who Registered, and it paid only 3 places. I missed it and was too late to register. Im sure someone at UltimateBet got their A** reamed for that one. I checked back the next day to see if I could get in on the $Gravy$, but there were over 100 ppl registered. These
poker sites do make comperable decisions as to "Guaranteed" prize pool payouts and predicted # of entrants. Its very rare when they have to put in the rest of the prize pool because of not enough entrants, but it does happen.