Establishing, growing and engaging a social audience is simply part of doing business in 2017. And 90 percent of marketers said social media is important to their businesses in the 2016 Social Media Marketing Industry Report.

63 percent of marketers commit six or more hours per week to social media, while 19 percent spend more than 20 hours a week. In addition to time, we spend a lot of our marketing budget on social media.

Social media advertising budgets have doubled worldwide over the past two years — going from $16 billion in 2014 to $31 billion in 2016. Come 2019, those in the U.S. alone are expected to spend $17.34 billion on social media advertising.

While most of us are regularly analyzing our social media efforts, 58 percent of marketers said they were not able to measure their return on investment (ROI). In essence, we’re investing a lot of time, money and energy, and we're not quite sure whether it's worth it.

That's why The Harvard Business Review has conducted 23 experiments over the last four years involving more than 18,000 people. They wanted to research whether attracting and engaging social media followers leads to increased sales.

The researchers focused exclusively on Facebook because it's the dominant social network. Though, they believe their findings apply across all social media platforms.

Here's what they learned — and what you should know, too.

Do Facebook likes impact sales?

  • Across 16 studies, they found no evidence that following a brand on social media changes, affects or influences people's purchasing behavior.
  • Seeing a friend like and engage with a brand on Facebook had no effect on the purchasing habits of other friends.
  • Boosting, sponsoring or advertising brand content to followers can have an impact. When a brand paid Facebook to display two posts each week to members of the group, those people participated 8 percent more.

How to make Facebook work better for your brand

Share and cultivate endorsements. Sharing and promoting engaged customers' posts like a positive review or experience provides significant value to influencing behavior. Gather those posts, share and boost them. Or try influencer marketing.

Go beyond the like. For social endorsements to work and hold the power of word-of-mouth referrals, people need to know more. They want to know their friend is actually using your product or service and likes it. To get this content out there, try including a share button after someone makes a purchase or encourage them to leave a review on Facebook. The research did show that tactics like this can help influence online friends.

Listen to your people. Those who follow and engage with your content on Facebook are going to be some of your most loyal customers. Create boosted, targeted content that asks them to submit user-generated content or leave feedback about a new product your brand is testing.

Less than half of marketers (49 percent) said social media has not helped them improve sales, according to the 2016 Social Media Marketing Industry Report. But 92 percent of marketers who invested six hours a week on social do believe it increased exposure.

Using the data and insights above, though, your brand can likely improve sales and increase exposure even more.