Unfortunately, this mostly started with the video game industry. EA were about the first to do it on a major scale. They figured out if they could get the community to do most of their final QC for them by running invite only Beta tests, people would freak out wanting in. They make sure the ones getting in are all about the new game, spread it on forums and among friends and the next thing you know, they've got a rabid customer base ready to plop down that dough!
Most of the time, the game drops are a slew of problems and most of the people who Pre-bought are aggravated by the time they get their product, which rarely lives up to the hype.
I thoroughly feel that paying for things you haven't seen or tried puts the manufacturers in complete control of the situation and is terrible for us, the consumer. Let's keep them honest and prove that they've put in the work to earn our hard earned dollars and cents!
I'll step down off my soapbox since my batteries are charged and there's shiny stuff in them there yards! HH!