i've seen few times on sitepoint - most of them are experienced buyers and they dont want to take any chances - there are many frauds and scams in web business as they inflate revenue and make a story which is too good to be true, of course one should have an eye for it to know that. also this practice is very common amongst small non-web businesses (convenience store, gas station, laundromat etc.) and now it is becoming popular on web as well...