It has become common practice for financial services firms to use Twitter, Facebook and YouTube but there are a raft of smaller, newer social media tools, such as Pinterset, tumblr and Instagram, that have yet to be tapped.

Launched two years ago, Pinterest had secured 11.7 million unique users by this January, according to comScore, making it the fastest site in history to break through the 10 million barrier.

In a white paper, Andy Rooks from research house Corporate Insight argues that: "The rapid growth and popularity of Pinterest has made it impossible to ignore, and financial services firms should consider developing a presence on Pinterest as part of a larger social media strategy."

Although Corporate Insight says that no financial services firms are using Pinterest yet, Banco Sabadell has recently begun adding 'pins'. The Spanish bank has created seven boards to showcase photos from tennis tournaments it sponsors and YouTube video interviews with celebrities such as Barcelona FC coach Josep Guardiola.

Sabadell's decision to ignore actual banking is in contrast with State Bank & Trust, a small Georgia-based institution which has also moved early to use Pinterest but has taken a different approach to content, posting images from its brochures and adverts.

So far, neither bank has secured much momentum, with just eight and 32 followers of their main pages respectively, but Corporate Insight offers some tips on how financial services firms can make the most of the site:

• Retirement: Interactive, image-centric retirement marketing campaigns
• Savings and investment goals: Posting photos of savings and investment goals
• Credit card rewards: Pinboards can be used to showcase credit card reward options, from merchandise to travel, and firms can encourage members to post photos of different items and experiences they've redeemed with their points.
• Lifestyle: Credit card firms can post photos from sponsored events such as concerts, sports games, and other partner venues. 
• Corporate Mascots: Dedicated corporate mascot pinboards featuring proprietary imagery detailing the mascot's activities.
• Contests: Holding contests or sweepstakes via Pinterest to gauge public sentiment. For example, followers may vote on preferred reward items by "liking" or "repinning" an image.
• Charitable giving: Pinboards can be used to highlight firms' various charitable initiatives. This could include images of the organisations or action shots of employees volunteering. As a way to engage with followers, firms could encourage them to post pictures of charities that they support.

Says Rooks: "Social media is a critical way for companies to communicate with their clients, prospects and other targeted audiences on a personal level, and Pinterest provides another channel for this."

Finextra verdict: Another day, another social media tool for banks to get their heads around and (like it or not) we think that Pinterest is one that really does deserve their attention. According to Experian Hitwise, last month it became the third largest social network in the US, surpassing that old-timer LinkedIn, and the inevitable rumours about a takeover have begun, with a $1 billion valuation bandied around in the wake of the Facebook-Instagram deal.

So, banks should probably use the site but how they do so is a tougher call: we certainly think Sabadell is doing a better job than State Bank & Trust at the moment. However, the key to any social networking site is, to state the obvious, the social networking - being interactive - and that's something that neither early adopter has done yet. Corporate Insight's suggestions for contests and charitable giving seem a sensible place to start.