Social media is a powerful tool for unions to communicate with their members and potential members, but it is no magic bullet and won’t automatically cause union messages to “go viral” or see a large upsurge in new members.

With Facebook’s user population now exceeding one billion people, most unions are establishing a Facebook page and setting up Twitter accounts. But be careful: it’s important to know what social media can and cannot do.

Contrary to what you may have read or heard about social media (especially in the aftermath of massive “success stories” like Kony 2012 — remember that?), sites like Facebook and Twitter don’t actually drive action.

I’ve argued that social media is a very soft influencer that contributes to and builds upon a person’s engagement with their union. It’s usefulness for unions comes from its links to the Consistency and Commitment Principle — where people are more likely to do something they publicly say they’re going to do — and the Power of Weak Ties, where people are subtly influenced by what their peers do and think.

Simon Dell, a marketer and columnist, recently wrote an article that challenged the notion that Facebook was in any way effective in “driving sales”. He now recommends that clients focus on face-to-face interaction with potential customers, and cites working with a small pet food company that gives out samples at local dog parks rather than via their Facebook page.

Needless to say, I think Dell is on the money.

Face-to-face contact is the most effective way to change someone’s behaviour and attitudes. The whole purpose of digital campaigning and social media, as I’ve argued for some time, is to facilitate and strengthen those face-to-face interactions.

Dell cites some numbers. For example, Facebook page updates are seen by between 10-16% of page fans. This compares poorly to the average of around 25% for email, and even higher (90% Dell says) for SMS text messages.

Remember when General Motors dumped its Facebook advertising? This was due to the woeful returns that their Facebook ads were getting. Less than 1 percent of ads would result in a sale!

In the online world, email is by far the most effective way to communicate with your members and supporters — and search engine ads are still the most effective way to find potential members.

But nothing beats face-to-face. Unions have known this for decades. The purpose of social media and digital campaigning and communications is to support those on-the-ground activities. Once you’ve got those new members, social media should be a part of the mix — along with emails, direct mail, phone calls, and personal visits — to keep them.

As for social media… well, it needs to be purpose-driven. Never set up a Facebook page or Twitter account “just because”. If you don’t have a plan on how you can use social media to drive your real-world campaigning and organising success, don’t bother with it. What is your union’s social media strategy?