guaranteed cash prizes

i was reading on pokertips.org about internet promotions and came across something interesting. if a site guarantees a certain prize pool, say, 250K, a 1000K buy in, if there aren't at least 250 players then the site makes up the difference. well what if 5 players entered? would that mean that the site would cough up 245K? surely not, right? can they just cancel a tourney? does it say the minimum entrants for these tourneys?
just wondering