The Merc Starter Pack is most likely from here: http://www.gamespot.com/articles/dirty-bomb-beta-giveaway/1100-6426871/

It's a shame it's buggy, would have loved that competitive advantage :)

i think you're wrong sir. that would be a misleading giveaway and a giveaway for a beta key, which are strictly forbidden on steamgifts. i'm sure giveaway creator wouldn't do such stuff.