I'll take myself as an "average" of all the PS users since I'm sort of middle of the road not casual but not super hardcore must play everything gamer.
As a PS Plus subscriber I've paid $50 and so far have gotten:
WipeoutHD 15 month rental.
A bunch of minis 15 month rental.
Syphon Filter 15 month rental.
Other things which I would have bought/gotten if I didn't already own:
Critter Crunch 15 month rental
$2.50 of of MK II
So, taking me as an average case, the "average" PS Plus user has received $2.50 worth of discounts on games that they want to buy and have 1 PSN game, 5 minis and 1 PSOne game on a 15 month rental.
So far for one month of service, I don't think that's half bad. Obviously there are people that wouldn't buy any of the games on discount or who already bought CC, WipeoutHD, Syphon filter and all of the minis haven't received much yet but I think the average PS Plus user has already gotten a few bucks worth of discounts and a few good games to "rent" for a year already.
