What if you could spin round the customer acquisition the other way? If one of the challenges in getting people to use a mobile currency is getting the details of how they will deposit their funds to the account, then why not ensure that point of pain is only presented after they are hooked into the system.

Can you think of another reason why Facebook would allow you to run up an initial overdraft of their Facebook Credits? The credits can be used for a wide range of third party services, especially in popular games such as Farmville.

The process is simple, when you go to use credits in the game, and Facebook would normally debit your account, you can instead opt to receive a bill from Facebook for the credit purchased. When you go to buy more, you’ll naturally be offered the option to repay the balance, but you can carry on spending and staying in the red, and becoming more familiar with the system before buying Facebook Credits.

But the job for Facebook is now done, the user is comfortable with the credit system, they’ve tried the entire process, and the pain of adding card details is now minimised because they know everything works. They are going to do the conversion themselves.

As InsideFacebook reports, this isn’t a global feature and is likely being trialed on a subset of users to find out the levels of acceptance, the value of credit given that has the best balance of risk and acquisition, and how many people actually pick up the option. I’d expect to see this rolled out to a larger audience in the near future, and as they do so, a number of other virtual currencies are likely to look on at the results. Of course Facebook has large pockets and hard cash to back up these transactions, so it’s not easily replicated, but as an option to gain traction with customers it has a lot of merit.