I just found out that the Viggle app, used to collect points by watching TV shows or listening to music, offers B&N gift cards at the rate of $5 per 15K points. I currently have just over 90K points, and there are some indie ebooks I've got marked to buy as Nook books because Kobo doesn't carry 'em and I don't want to convert 'em from Kindle format. A couple of $5 cards will take care of that right quick!
Viggle's not exactly a fast way to get points, though. Watching TV gets you a point per minute (you "check in" once and it assumes you watch 'till the end or until you check in to a different show), and you can click to play ads that are usually 5 points each for a 15 or 30 second spot...although sometimes they give you a 100 or 175 point ad. They used to only offer one or two ads at check-in, but lately I've been able to get a string of about 20-25 if I stay on it. (Mostly repeats, but I just mute the volume anyway.) Listening to music is 25 points/song, at a max of 20 songs/day, but you can only ever check in with each version of a song once. All the same, if you watch any TV at all, there's no harm in building up points while doing so.
One other point: Viggle's not a content provider. You use it by turning on your TV or stereo, hitting a button on the app, and letting the app listen to the content to recognize it. And yes, you can do other things with your device while checked in - just not while playing ads. It also works with time-shifted and On Demand content, at least within a reasonable period of time.
I'm not trying to sell anyone on Viggle - but it's free and gives me points for stuff I'd do anyway. No complaints here!
ETA: The 20 songs/day limit has apparently been lifted, or at least raised.