Since January 2013 the $402 million credit union has grown its Facebook fan base by more than 3,900 to 5,813. With that strategic goal met, February 2014 began a focus on generating loan leads, which has so far resulted in closing an additional $498,000 in loans from that channel alone, Schaffer said.

"CitizensFirst stepped it up and got aggressive," Schaeffer said. "Instead of offering contests to up the fun factor or boost enthusiasm they decided to go after leads, and it's paid off. So those who say you can't prove ROI, yes you can."

When it comes to contests, while many get bogged down on themes, Chatter Yak! found that simplicity has been key, Schaffer said. Keep entry forms to the basics: Name, address, phone, primary email and if they are credit union members. If they are not members, ask a leading question associated to a current promotion with options to learn more, she said. Schaffer also advised credit unions to have a select group of specialists to follow up on leads.

"Not everyone is a people person or able to pick up the phone and represent the credit union the way you want and reel members in," Schaffer said. "That's the goal. To sell your credit union the best you can and inform the member how you can help save them money and make their financial lives better. So select one or two standouts in the lending department rather than passing leads off to the entire department."

Making the most of Facebook's AdTracker to run contests is also important. Schaeffer said the credit union's last contest generated so many entries that it nearly crashed ChatterYak!'s server, as it contained over 78,000 data points to be extracted and delivered to CitizensFirst. The June campaign alone landed 786 entries from which 263 loan leads were produced, and brought in an additional $187,978.14 in consumer loans.

"A lot of times credit unions think that they're dealing with the Facebook of seven years ago when it was fairly easy to reach a vast number of people organically," said Joseariel Gomez, CEO of Shastic, a technology company that specializes in providing online loan generation solutions. "But the truth is that in most cases, they're late to the party and nowadays trying to grow your reach on Facebook requires a budget, just like growing your online traffic does."

Gomez said it's time for credit unions to rethink how they look at Facebook.

"It's essentially the opposite of how your online channel works. On the web people look for pages (content) but on Facebook, they expect content to come to them into their newsfeed and to be highly engaging," he said. "So it's not enough to simply recycle the static content that you have on your website. You need to provide content and a user experience that is very engaging, that looks good, that is simple and that flows naturally into your online lending process or online buying process for other products."

Read more: How Alliant used social media to boost loan volume …

Since 2009, Chicago-based Alliant Credit Union has been steadily and strategically connecting with members via Twitter, Facebook, Google+ and LinkedIn.

Looking to engage in more meaningful ways with its more than 13,000 Facebook followers while attracting younger members, the $8.1 billion credit union launched an auto loan campaign with Shastic's Calcubot Cloud as a quick, user-friendly way to calculate a loan payment.

Members were able to apply for a loan directly from the application and save their loan calculations in the cloud for later access, share the estimated payments with friends on Facebook and opt to receive alerts when interest rates fell to a desired level without having to reenter their information. Alliant promoted Calcubot on its homepage, Facebook and its other social media channels. Conversions were tracked through a promotional code.

In the first four months the campaign attracted some 6,400 visitors, of whom 82% received an auto loan estimate. Among the 478 qualified prospects 39% submitted an application and 7% funded loans totaling $887,043.

"It was something new for us so we weren't sure what to expect, but we got an 86% engagement rate," said George Balchev, manager of digital channels for Alliant. "This may sound very broad but there is a significant benefit to having a good plan and measurements in place for how your social media efforts can be used to bring value for your members."

Alliant's strategy has evolved as part of the digital marketing mix to not only have an ongoing conversation with members but also connect to other campaigns, products and services.

"Think about what kind of interactive experiences or content we can offer as part of our marketing strategy to align our social media efforts with our core product," Gomez said. "I think financial services are a big part of everyone's lives and it's also an area where a lot of people are not very literate and intimidated due to the lack of knowledge.

"This creates the perfect opportunity to use new platforms such as Facebook or mobile to connect and develop relationships with members and potential members around their current financial needs and tie it naturally into your sales processes."