Why are we paying for xbox live still!

Like many people I've been hooked on the new Call of Duty game for xbox 360. And like many "360" owners I have downloaded the new xbox firmware, or as Microsoft calls it, The "New Xbox Experience". Overall I like the new update and prefer it over the old one, although I wish there was a type to search feature (you still have to scroll down a list when you search for some thing) but other than that it's all good. The avatar feature is pretty Wii esque and apeals to a much younger crowd. But what really gets me is the advertising that has now found it's way into our gaming consoles, I guesss it was unevidible. But with all the new loot I'm sure microsoft is making,by selling advertising space on xbox live, why do we still have pay 50 bucks for a subscription then pay for content we download? I mean playstation 3s' online network is free and you basically do the samething as xbox live?
Maybe it's one of those Microsoft things I'll never understand (like always).