Playdom, one of the leading social gaming networks, announced today that they are launching a line of prepaid cards that will soon be available at Target, Walgreens, and 7-11. If you had any doubt that the social gaming space has become a big business, this should make things clear. The cards will now be available at more than 150,000 retail locations and can be used to purchase in-game currency on Mobsters and Sorority Life, two of Playdom’s largest games.

Just this morning we learned that Zynga is partnering with InComm for their own set of prepaid cards. The timing of these announcements are most likely not coincidental considering the two companies are fierce competitors. Zynga is even in the process of suing Playdom for stealing trade secrets. Personally, I’m not big on purchasing virtual credits but its a growing business.

Zynga is rumored to be on track to earn around $200 million this year (although we’ve heard a couple high ball projections as well). The fact that social games are now getting a retail front for them illustrates just how many people are playing them on Facebook and other social platforms. Purchasing in game credits is not exactly a new thing however. Games like World of Warcraft are already selling game credits at retailers worldwide.

So run on over to Target or Walgreens, stack up on some junk food, beer, energy drinks, and whatever else you like to consumer while gaming, and purchase your Mobsters game credits. Now you’ll be able to purchase weapons and destroy the competition! I’m guessing that this is just the beginning of a growing trend. So will you be purchasing game credits the next time you checkout from your local retailer?