Facebook also has tools that enable you to attract others who don't know you by showcasing the same traits that your closest friends like the most about you.

Social Media Marketers know about Facebook Lookalike Audiences but I doubt if most Email Marketers do. As its name implies, it's a way of targeting ads to Facebook users who aren't your followers, but who "look" a lot like them.

Your email subscribers are people at that next level of intimacy in their relationship with you. So what you want to do is use Facebook to present yourself to strangers who share characteristics similar to your most avid email readers.

Step One: Identify your most avid email readers
The same software application you're using to send emails to your contact lists will enable you to identify your most avid email readers. The general definition of an "avid reader" is anybody who has either opened or clicked in any of your emails in the past 30 days.

Of course, you want to exclude anyone who has just recently joined your email list. You're interested in those contacts who know you the best. Newbies may have read your first email or two, but they don't really know you, and they even may end up dropping out just after a few days.

If you don't have a very large email list, or you don't send all that frequently, then you might want to increase the time horizon to the past 60 days. Anything beyond the past 90 days is a stretch.

Step Two: Export these avid email readers to a CSV file
Your email software application will let you export these avid readers into a comma-separated value (CSV) file. You want to include your contacts' email addresses in the export -- that's the bare minimum. If you have the data for your email contacts, you want to include your contacts' first names, last names, city, state, country, and zip code of residence.

The reason why you want to include this information in your exported contacts file is so that Facebook can match them up with your Facebook followers. Don't expect a 100% match. How close you get to 100% depends entirely upon how many of your Facebook followers also subscribe to your emails AND use the same email address for emails as they do for logging in to Facebook. (Hint-- using Facebook Lead Ads to capture email opt-ins will increase that match).

Step Three: Create a Facebook Custom Audience from your Avid Readers File
Log in to your Facebook business account and follow the step-by-step instructions to create a Custom Audience From a Customer List. When you're importing your file, there's a few things you'll need to think about in order to strike the right balance. The more contact profile fields you include in your import file, the better the matchup with your Facebook followers. But the more fields to match accurately, the fewer number of your followers will exactly match those criteria.

Facebook recommends that you start with a Custom Audience size of between 1000 and 50,000 as the baseline for a Lookalike Audience. Your starting list of avid email readers should be about 20% to 50% larger.

I recommend starting with email address and last name (if you have it) to start your matching. If the number of Facebook followers is manageable, go no further. ​If the size it too large and you're worried about blowing your ad budget, then gradually increase the number of fields to match until you get to a size that you're comfortable with.

Step Four: Create your Lookalike Audience based on your Avid Readers Custom Audience.
Next, follow the instructions for Creating a Lookalike Audience, using your Avid Email Readers Custom Audience as its source audience.

Remember: if you set too large of a Lookalike Audience, then those selected Facebook users may not look at all alike your own followers.

There you have it! Now you can start targeting your Facebook ads and promoted posts to your Facebook Lookalike Audience to gain more followers.