Before social media, brands spoke for themselves. A Coca-Cola billboard was almost certainly placed by the beverage company. Today, a social media post about Coca-Cola can come from anyone.

For brands, that can be a double-edged sword. On one hand, consumers won't hesitate to share a subpar experience, and 97 percent of them read online reviews. On the other, a happy customer who tells the world beats any ad or mailer that money can buy.

So how can brands get more of the latter and less of the former? Fast growth requires three relatively new disciplines: social, experiential and influencer marketing.

I'm a big advocate of putting employees first -- when you do that, the employees give customers an amazing experience. Your employees' hard work and thoughtful efforts develop loyalty with your customers. Those customers are then well positioned to become advocates.

One company I consulted was hesitant to give customers the reins when it came to word of mouth; the CEO was worried customers wouldn't portray the brand correctly. But when we did a marketing cost analysis, we found the company could have saved $57,000 in one year if it had encouraged social media advocacy among its customers. In other words, it could have grown faster at a lower cost.

Brands can't force customers to say good things about them on social media. But by using four tactics, they can make it more likely:

1. Prioritize authenticity.

Although brand authenticity matters to consumers of every generation, Millennials care about it most: Nine in 10 say they prefer "real and organic" over "perfect and packaged." Millennials care so much, in fact, that three in 10 in 2017 said they'd unfollowed a brand after seeing what they perceived to be inauthentic content.

Authenticity may be tricky to define, but it's not so tough to implement. Mahesh Chaddah, co-founder of travel site, says brands should be transparent in their communications, provide actionable tips and minimize superlatives. Chaddah also considers it critical that brands build their voice, in part because they can't curate user-generated content -- which 85 percent, of consumers see as more influential than other forms of brand communication -- until they've developed their own voice.

2. Build a bench of influencers.

There's a reason that, according to influencer marketing platform, 93 percent of marketers use influencer marketing. Six in 10, in fact, are growing their influencer budgets in 2019. When an influencer suggests a certain product or service, her followers want to be associated with it, too.

Influencers are particularly effective in certain sectors, such as cosmetics, but beware that there's no such thing as a one-size-fits-all influencer. There's a difference in the potential fit of a witty, sophisticated influencer versus the fit of a bubbly, charming influencer -- it all depends on how the influencer's voice fits with the brand's voice.

3. Set up stellar experiences.

Nearly three-quarters of Americans prioritize experiences over products. Instead of giving away pens or water bottles and hoping they get seen around town, give customers an experience. Not only will they appreciate it more, but they're more likely to share it on social media, which is more scalable.

What sort of experiences should brands put on? Brand alignment and shareability are critical. When Greater Palm Springs Convention & Visitors Bureau wanted to get Manhattanites to book direct flights from New York City, it asked consumers to attack giant blocks of ice with whatever tools they could find to "break out of the chill" of winter. Not only did participants find warm-weather prizes inside, but one lucky New Yorker got a free trip out of the event. The activation aligned with Greater Palm Springs Convention & Visitors Bureau's mission, plus it caught the attention of hundreds of New Yorkers (and untold more) on social media.

4. Incentivize sharing.

Even the strongest content isn't much use if it doesn't get seen. Use small rewards -- such as a product tasting, facility tour or service credits -- to encourage consumers to push brand-positive content on social media. Given how valuable user-generated content is, give an additional reward if users can drum up online attention for their own post.

Oscar Mayer leveraged the reciprocity principle by giving away hot dogs and offering a second coupon for consumers who submitted a "Taste-a-Monial." The twist is that Oscar Mayer increased the value of that second coupon by 50 cents for every 5,000 shares the Taste-a-Monial received until the coupon reached the price of another pack of hot dogs.

At most companies, a single quarter of marketing spend is worth thousands of packs of hot dogs -- not to mention the time savings. Companies may lament the loss of control when customers become their advocates, but it's the best way to maximize the loyalty those brands have worked so hard to build.