Gotta love the communication between Target and the TMs. I only heard of this because it came up as another app by Target when I downloaded Cartwheel. Prices aren't amazing, buut, for movies that aren't on Netflix instant watch and aren't in the Redbox at the moment, could come in handy.
For instance, they have Despicable Me renting for $2.12
It rents for $2.99 on Amazon. I might go with Amazon if I still had a Roku despite the price difference, though.
The Amazon vs. Target competition is kinda funny, though (it seems like that's what this is). I remember they used to have a partnership and you could order from Target through Amazon.