Despite digital marketers' recent shift of focus onto quality of engagement, rather than just quantity of followers, social media marketing is still often thought of, primarily, as a tool for increasing brand awareness.

Want to reach a new demographic? Use social media. Want to expand your reach to an international audience? Use social media. Want to increase unique visitors to your website? Use social media.

While these are all valid, and important, uses of social media marketing, it's just as important to focus on how social media can function as a customer retention tool. How are you using it to connect with the customers you already have? How are you using it to nurture those relationships, allay concerns, and offer them relevant information?

If, like many brands, you've found yourself neglecting this area of your social media marketing, take a look at these 4 ways you can use social media marketing to improve your customer retention rates.

1. Express gratitude

Sometimes, those of us on the digital marketing side of things can forget to express our gratitude to followers who post on our timeline, re-gram an Instagram post, or write a Facebook review.

Just as every social media post we create takes time out of our busy schedules, each time a follower engages with our brand, they're choosing to spend their time with us. Sometimes it may be as little as 30 seconds. Other times, they may take 15 or 20 minutes to write a thoughtful post, or share something that's important to them.

Either way, a small expression of gratitude on our part - even a quick "Thanks for the comment!" - can go a long way toward making these engaged customers feel appreciated.

2. Employ social listening tactics to identify what your customers want from your brand - and then give it to them.

Social listening, or keeping track of social conversations that include certain phrases or topics, can be used for many purposes - including customer retention.

Using social media management tools like Buffer or Sprout Social, brands can monitor what their customers are talking about online. That information can then be used to brainstorm ideas for content, social advertising campaigns, giveaways, and more.

3. Identify and nurture potential brand advocates

Do you have social followers who are significantly more engaged with your brand than the majority of your other followers? Perhaps they enter every contest, or they start conversations about your brand online, or they offer suggestions and comments on a regular basis.

These followers could be your next brand advocates - online influencers who share positive ideas and sentiments about your brand with their followers.

Nurturing brand advocates isn't exactly the same as influencer marketing.

Although both rely on the fact that customers are far more likely to trust another customer than they are a brand, influencer marketing usually requires a more structured agreement than working with a brand advocate.

Influencers might be paid a certain amount of money for a specified number of posts, for example.

Brand advocates, on the other hand, are people who already love your product or service and are already engaging with your brand. Nurturing these brand advocates could take the form of sending them a free gift or a coupon, as a "thank you." You could invite them to a members-only section of your website and waive the membership fee. You could offer them an early look at your latest product offering.

Your first goal is to sincerely show your appreciation for them and how they've been spreading the word about what you do.

Your second is to improve that relationship further by generously rewarding them for their loyalty.

If you can employ these two values, sincerity and generosity, throughout your social media marketing, you won't have to dig for brand advocates. They'll show up on their own - and what's more, they'll stick around.

4. Give gifts

Contests aren't the only time you can offer a gift to your followers. Giveaways can be employed any time, for any reason - or no reason at all.

Giving gifts to customers who've been engaged with your brand for some time is a wonderful way to convey to your customers how much you appreciate their loyalty. The gift certainly doesn't have to be big - a 10% off coupon, a copy of your latest book, or an extended free trial are all great possibilities.

If you make this kind of regular gift-giving part of the way you do business, your customers will notice. They'll also be receiving even greater value from their relationship with your brand, which will encourage them to keep that relationship going.

Social media can be a highly effective way to improve your customer retention rates. For more, read my post "3 Amazing - and Free - Marketing Tools for Small Businesses."