The lure of social media continues to attract Australia's big banks, with NAB being the latest to announce a Facebook initiative. On Friday, the bank announced an exclusive trial with local social media marketing start-up Tiger Pistol, which will allow small- and medium-sized businesses with an NAB Transact account to set up an online store and accept credit card payments via Facebook.NAB is not the first bank to fall for Facebook's charms. Earlier this year, Commonwealth Bank announced that it was planning an application for 2013 that would allow its customers to both access their accounts and conduct transactions from within Facebook. NAB's approach, however, is to provide a secure payments platform - essentially, playing PayPal at its own game - which businesses can use to make sales from within Facebook, so-called F-commerce transactions. To use the service, which is still in the pilot phase, businesses with a Transact log-in can pay A$29.95 a month to Tiger Pistol, which will provide them with an online store platform that can be accessed from inside Facebook. A clip of that $29.95 monthly payment will go to NAB in return for access to the Transact payments system.Customers can use their credit cards to make a payment, with NAB's Transact platform handling the payment side of the business. Tiger Pistol co-founder and CEO Steve Hibberd said that around 20 companies have trialled the service thus far.According to NAB's executive general manager for direct banking, Sam Plowman, the arrangement with Tiger Pistol simplifies some of the technical issues associated with setting up an online store within Facebook, while Transact securely handles payments. This, he claimed, would give small- and medium-sized businesses the opportunity to hang out a shingle on Facebook, which he described as the busiest street in the world.The jury is still out concerning how much of the total e-commerce market Facebook will ever be able to command. With F-commerce still being viewed as a small and micro business sales channel, a report issued in September by Forrester Research found that less than one per cent of all online sales were currently being made via social channels.