Social advertising has been made so accessible that anyone with a credit card can click a button and sit back while the numbers roll in.

But what do those numbers really mean? How do you know if social media ads are working? Is social advertising a worthwhile investment to grow your business? 

The answers lie in three measurable numbers: Reach. Engagement. Conversions.

Reach is the number of people who see, or have the opportunity to see, your post. It is often the most gratifying number to watch grow ? a single click can take a meager reach of a dozen people and drag it into the hundreds in a matter of minutes. 

That can be a big ego boost. But what difference does it make if you are not reaching the right people?

You do not want just anybody to see your message. You want the right people ? your ideal customers.

Which means you need to target your ads.

Social media has a leg-up because people voluntarily offer details about their lives. They spend hours sharing interests, posting updates, liking and commenting. Each click and keystroke is another data point to draw from. 

Not only can you target to people who are already your fans, you can identify the people who look like them, who click the same links, and who like the same type of post. 

Before clicking that tempting ?Boost? button, make sure you know the 5 W?s of digital marketing so your reach is not wasted on people who are not your ideal customers. 

Engagement statistics give you insight about how people interact with your post. 

Clicks, likes, shares, comments ? all these are rolled up into a shiny package labeled ?engagement.?

This is where the social part of social media becomes so important. 

Your business could easily post an article, photo or link in an ad and then forget about it. But why would you want to? 

When a new person interacts with your business on social media, she is raising her hand. She is no longer a name or an email address ? she just became a prospect. 

Engage with handraisers. Reply to their comment, thank them for sharing, add them to a remarketing list. But for goodness? sake, do not let them sit there.

At the very least, learn from them. Engagement tells you what content is working so you can focus on the message that resonates best. 

The same messaging that lets you turn holiday slowdown into treasure can help you create an effective ad on social media.

There is another bonus hidden here. 

Building engaging content on social media can have an impact after your ad is done running. 

The best social media content is like a snowball rolling down a hill, collecting more snow as it rolls, growing faster and larger until it becomes unstoppable.

The best content is evergreen. It can go viral, stay relevant and continue to resonate with customers even though the ad spending has stopped.

To really know if your social media advertising is working, you need to look at one more number: conversions. 

Are those engaged viewers converting into customers? Do they care about the message you are sending, or did they simply click ?like? out of habit as they scrolled the page? When they click onto your Web site, do they immediately bounce away or do they continue to interact?

Conversions may be the most important number to consider because of its direct impact on the bottom line of your business.

Engagement and reach are great for gaining awareness, growing your audience and building your brand ? and there are times when that is enough. But if you never convert that audience into customers, you will never grow your business.

EACH OF THESE numbers is one leg of the return-on-investment stool. 

Without conversions, you may be able to balance for a while, but you are likely to tip over sooner or later.

Social media advertising can have a huge bang for your buck, but it has to be executed strategically. 

The best ads reach the right people, build social engagement and grow your business.

When you need to know if your social ads are working, turn to those three magic numbers.