I Got Stiffed

Just curious, why should a internet deal with someone from a web forum be any different from a brick and mortor retail sale. Pick out your item, go to the register and PAY for you item BEFORE it leaves the store. I have never been in a store that lets me carry the stuff out put it in the back of my suburban and then go back in and pay. We need to treat every dealing that way. Helps to prevent this kind of crap from happing. Just my 2 cents