How do you mean that something wasn't free?
I work in retail, and have noticed that a lot of people either want money off something or something 'chucked in' for nowt, so I can see why the word free gets used a lot. Its an easy way to get people listening.
For instance, if I sold a laptop at £699 with no case people would want the case chucked in, but if I charged £749 with a 'free' case it would look more attractive to some people. Later, to look even better, I could drop the price to £699 without the case and say 'sale - £50 saving!', but the customer would then pay for the case.
I don't know if this is how the marketing departments of companies work, but it sure sounds logical if you want to get the sales.