I don't know if someone is interested and/or if this has already been posted, but just to let you know that here the bundlestars guys are giving away steam keys for pid.
At the moment of writing this, there are 91999 keys left. You must only sign-up through steam and subscribe to their newsletter. Although I have not activated it yet, I got the key on my mail already.
Source

Yeah someone already posted it here but thanks for sharing. Got mine already ;)

I appreciate you letting us know. I didn't see the other thread so the only reason I have Pid right now is because of your thread. Thank you +1 :)