GameFly comes in two flavors initially. A one game plan is $14.95 and a two game plan is $21.95 per month. If you are a member in good standing, they will offer a 3 or 4 game plan ($28.95 and $35.95 respectively) later.
If you've ever used Netflix, then you know how to use a online rental service.
You choose a list of games and place them in a queue. You can keep the games for as long/short as you want. When a game is a returned, GameFly ships the next game in your queue.
Nearly all games that I've wanted have been available and the ones that weren't were only a few days (at most) wait. The availibility will show next to the game.
You have the option to keep (buy) games that you rent. This is a good deal if you like the game. Sometimes there can be a $10-$15 savings off new games. Shipping of the case and manual is either free or a nominal charge of like $2. The case and manual are opened (obviously) but are in pristine condition when you get them.
Downsides:
GameFly is out of the Los Angeles area. I live in Utah, so games shipped on Monday usually get to me on Wednesday (sometimes Thursday). Midwest/ East Coasters can expect longer times. Since GameFly doesn't ship another game until one is returned, the turn-around time for a game could be slow.
GameFly DOES have a service called FastReturn that works with the USPS. Basically, when you send a game back, the USPS will scan the barcode information on the prepaid return envelope and notify GameFly that a game is on its way. GameFly will then send out aonther game whilst a game is in the mail coming back to them. This can cut down the turn-around time.
However, not all Post Offices have this technology and there are reports that some USPS employees don't scan even if they have scanners :brick: .
Hope this helps.
Happy gaming!