It just seems a slight variant on selling practices in capitalism that's been going on since Jarkal was offering those slightly off figs at half price in Mesopotamia several thousand years ago. Supply and demand, fluctuations in market price and consumer buzz have always resulted in "sale prices" being the highest out there. Sure, being attached to the Internet can leave you more prone to targetted advertising, but it also let's you trivially source competitor's prices. In the end, nothing has changed except things move faster. If you're a bit lazy and don't price check, that's your own lookout. It's not some evil corporate manipulation. Works for me.