Personally I didn't find it worth it. Some months you'll luck out and get a game worth the $12, but realistically the "$100 value" is a bunch of shovelware garbage that you'll never even install or games that, while not bad at all, just don't interest you.
If your gaming style is to play any game for the experience of playing it, or you have extremely diverse tastes, I would say it is going to be worth it and you won't regret it. If you are more selective about your vidya or you are intent on gaming "efficiently" by spending time on games that you know you will enjoy, I would steer clear.
I've got kids, so I fall into the latter category. I don't really have time to spend hours sifting through games that I may or may not enjoy. If you enjoy experimenting and maybe finding things you might like but would've never given the chance otherwise, I say shell out the $12 for a couple months to try it out.