Some stuff is paid for - other stuff isn't.
Take Dead Space extraction coming with DS2 for PS3 -- that was defiently paid for, probably in the form of reduced lisencing fees.
L.A Noire content though was not paid for, the developers already said all the pre-order bonuses were originally intended to be on the disk -- it was space constraints that meant that wasn't possible and so Rockstar opted to use the content to make a little extra money. I expect the PS3 exclusive content is because of a difference in licensing costs between M$ and Sony (M$ charge a little extra for 2 disks, a fair bit extra for 3 discs, an insane amount extra for 4 discs and 5 discs makes it not worth releasing the game).
Portal 2 content was not paid for, SONY merely let Valve use Steamworks on PSN, Microsoft wouldn't allow this and so Valve gave PS3 owners some extra content -- though keep in mind the extra content is promoting the PC version of the game.
Was FF7 paid for when it was released? As far as i am aware SquareSoft was upset with Nintendo and SONY was either about to or had recently bought ~20% of SquareSoft... therefore i would say SONY 'paid' for the PS1 FF games.
