I just purchased Just Cause 2 from this site because it is cheaper than Steam. I completed my order and here is the message that I got.
"Our security procedure forces us to put your account on hold until security checks can be made. Please excuse us for the inconvenience, you'll receive your key in the next 8 hours".
LOL, in the site they are saying you will get your key immediately, if I want to wait for 8 hours I can go to shop and buy retail or pay higher and buy it from Steam. WTF is security check is also? You got my money, yes so give me my serial number. Meh, I won't use this GamesPlanet service be aware of that.

Ok, I got my key and activated on Steam but I won't use this service again.

To be fair, I've had the exact same issue with steam. But that's probably mostly down to living in a different country from my credit card at the moment. Missed out on the Toca3 deal cos my card wouldn't be accepted.

I don't trust their site too. Although Interplay was selling the Fallouts exclusively on GOG and GamesPlanet (Metaboli with a different name, isn't it?), before spreading them to Steam and etc.
It happened to me once, during the steam's holiday sale. But only happened on the last days, their system went nuts and stopped accepting my cards.

It is not a credit card issue. Also I paid with Paypal. I searched the forums and all of the users have the same problem with some games (some users are saying they have waited 3 or 4 days to get their key also support didn't answer them in that time). You must wait 3 or 4 hours to get your serial and this is so stupid I think. They are doing this manually I think, lol. Anyway I won't use this bad service again.