"Free" has increasingly become a weasel word in gaming. As an example, take "free to play", which is the dominant platform on mobiles and a big reason why I hate telephone/tablet gaming. You can play a base game for free, but in order to make it halfway enjoyable to play, you have to give the publisher easy access to your bank account. Basically, either wait several hours for something important to be created for you or pay money to speed up the process.
I have PS+, and I generally don't go for the "free" games myself. I have PS+ because it's required for online play on the PS4. I do occasionally take advantage of the discounts, but I'd rather pay up front and have unlimited access to the game for as long as I want it rather than have to keep feeding the machine. I was okay with that business model in 1984, but this is 2014 and I'm not okay with it.