To enable the highest accuracy tracking of Facebook Ads follow this guide on how to place the ThoughtMetric tracking parameter on your Facebook Ads.
ThoughtMetric Facebook Ads tracking parameter:
tmsrc=facebookad&tmcid={{campaign.id}}&tmsid={{adset.id}}&tmid={{ad.id}}
1.) Copy the ThoughtMetric Tracking Parameter
2.)Place the ThoughtMetric tracking parameters in the tracking area of EVERY ad in your ad account
Note: Updating ads will reset the learning phase, and will require Facebook to review and re-approve your ads. This should not dramatically affect ad performance.
How to handle parameters that are already in the tracking template
If you already have some tracking parameters in the URL parameters field, don't worry, you can use the ThoughtMetric tracking parameters in addition to any tracking you already have in place.
To use the ThoughtMetric parameters alongside your existing tracking template you will want to append our tracking parameters to the end of your existing UTM string by using a "&" symbol starting with the tmsrc parameter.
For example If you already had the following text in your URL parameters field:
utm_source=facebook
You would want to append the ThoughtMetric tracking parameters so that the end result looks like this:
utm_source=facebook&tmsrc=facebookad&tmcid={{campaign.id}}&tmsid={{adset.id}}&tmid={{ad.id}}