Marketers often find it hard to prove the ROI of social media investments. Here’s an easy way to quantify the value of recruiting people to like your Facebook page.

You will need:

A metric.

What is your goal in acquiring likes? Is it to increase sales, change offline behavior, or accomplish something else? Your Metric should reflect behavior that is measurable. For some metrics, such as sales, measurement is pretty straightforward; for others, such as brand attitudes, you may need to do extra work, such as administer a survey.

An invitation method.

You need to invite people to like your page. One simple way is to obtain e-mail addresses of people in your target market.

Then follow these steps:

Acquire likes.

Invite half your sample to like your page; this is your “treatment group”. The other customers form your control group. Record the group to which each customer is assigned.

Confirm your assumptions.

Check to see whether the liking induction worked–you need to make sure that a good chunk of people took you up on the invitation. You can approximate the number by looking at the increase in your Facebook followers at the time you issued the invitation.


Run some advertising on Facebook to expose your new recruits to your marketing messages. You can do this by paying to promote posts.

Check your response.

Measure the behavior you defined up front. Say it’s sales: If the average spend of those in the treatment group is higher than the spend of those in the control group, the difference is the value of a like. Of course, your results will contain some “noise”; for example, you might miss the purchases of people who check out using an e-mail address that’s different from the one you have on file. To increase accuracy, aim for a large sample size and make sure that your e-mail list as current as possible.

by Harvard Business Review Magazine, March-April 2017.