There are two main ways to track social media campaigns!
Method 1: Driving traffic to website or landing page
If you're driving traffic to the website through social media channels, the dynamic pool of numbers on the website will capture this "source" (e.i. Facebook.com) as long as you have the pool swapping for "all visitors," "All Visitors Except Direct," or if you have separate pool for those visitors "Web referrals from facebook.com." Then, you would see the social referral site in the source column of the dashboard when people called through the number!
Method 2: Tracking the calls directly from the social media channel.
If you want to track what calls are coming directly from the ad (for example, someone finds the Facebook page, and calls the number directly on the page instead of clicking through to the website) we recommend grabbing a static number and that should be the one that you insert in the contact section.
Simply Add a new number, select "Local" or "Toll Free" and configure. We recommend titling the number something along the lines of "Facebook" or whatever the social source is that you're tracking.
The above not only can be applied to Social campaigns, but to any type of referral si Yelp, Trip Advisor, and any other type of referral site you might be using!
Static Number Article