We don't usually recommend emulating cell phone carrier behavior, but this is pretty cool: Rdio now lets you combine accounts into a family account for a ~20% discount.
Combining two $10/mo accounts brings the total down to $18, and three accounts brings it to $23. You can add more than three, but the price per account jumps back to $10 per. It's a bit of a drop in the bucket, and it would be nice to just be able to add more than three users. And sure, you could just hand your account into over two buddies and sidestep the whole mess. But you'll run into a mess of errors when you try to use it simultaneously on, say, a PC and your phone. Probably better to just pony up the couple bucks for your own account.
You also probably don't want your friends' or family's activity showing up as yours in the Rdio feed; though if you're part of a group that's active on the service, the family plan could add another level of interaction. Regardless, if you have a few accounts in your house, free money just popped into your pocket. [Rdio]