Attention Cityville, Mafia Wars, and Bejeweled players, I bet you’d like to earn Facebook Credits by doing something you probably do all the time. A new loyalty service called Plink allows you to dine your way to Facebook currency riches.

Plink is pretty simple. All you have to do is join the program through Facebook connect, and register your most-use credit (or debit) card with your accounts. As you use that card at participating retailers, you will earn Facebook credits automatically.

Here’s the sales pitch, from Plink:

Plink was designed to be simple and easy for restaurants and offline retailers, among others, to implement. The program requires no POS (Point-of-Sale) integration; no paper coupons to be collected; no staff training; no interruption or slow-down to the normal customer transaction process; no tracking conducted by the restaurant or offline retailer; and no set-up fees, print costs or other merchandise to purchase. Restaurants and offline retailers simply pay Plink a percentage of the sales generated by Plink members.

Plink’s starting partners are Taco Bell, Outback Steak House, 7-eleven, Red Robin, Quiznos, and Dunkin Donuts. This means that there are over 25,000 places nationwide that you can utilize this rewards program.

The amount of Facebook credits you earn per transaction depends on the restaurant – each have their own terms. Right now, you can only register one card for Plink rewards. You can even register a card already linked to rewards like airline miles, forming a sort of super rewards card.

“Facebook Credits is the missing ingredient that’s been needed to connect social media to offline sales,” said Peter Vogel, co-founder of Plink. “Now with the ‘glue’ of Facebook Credits our national restaurant and offline retailer partners have a way to tap into the nearly 800 million users on Facebook, motivate them to become loyal customers, and reward them.”

So participating restaurants have a new way to promote loyalty, Plink makes a profit on each transaction, and FarmVille players get credits for dining out. Our verdict – sounds like a pretty tasty idea for a startup.

What do you think about Plink? If you play games that use Facebook credits, does this sound like something you’ll sign up for? Let us know in the comments.