They have annoucements under "Showcase" when you log into the program:
http://pcmedia.ign.com/pc/image/arti...1237874296.jpg

If they have a free game, a weekend trial or a $1 game, you just find the game in "Marketplace" and select it and it will give you the options from there. select full play pass and it should show what the price is. there might be a promo code for this one instead of "$0", haven't tried this on a tablet yet and the offers tend only last for a small amount of time, a few hours or a few days. Check their facebook page for the promos: https://www.facebook.com/OnLive