Well, originally I quite liked them. Now they are blacklisted -- so what happened?
Two things, really. First was that case where they gave me an invalid key. Claimed they were working on that with the publisher, but they never gave me a working key, or changed the contents of the key so it would work. It was only a few cents for a DLC, so I didn't even look into legal actions. But I already got careful after that.
Then they decided that they wanted to change their store credit system, and that they would just remove any credit customers might still have. With a very short warning period. In response to that I purchased something that I didn't actually want, turned off the newsletter subscription, blacklisted them on isthereanydeal, and never considered looking at them again ever since.