Custom Audience is a well-known feature of Facebook to target your ad campaigns using your own target list.
Even though Google limits the advertisers by only uploading email information, Facebook gives additional options such as mobile phone numbers, which is a very substantial resource for many industries including Telco companies.
Facebook gives an excellent opportunity for advertisers to dynamically set Custom Audience targets by exposing its Custom Audience APIs in many languages. Here, you may find Java SDK https://github.com/facebook/facebook-java-ads-sdk
If you need to update the user list of your Custom Audiences dynamically, you need to integrate your working environment through these APIs. Here, you will need to grant the access using the parameters below.
- Facebook App Secret Code
- Facebook Ad Account ID
- Facebook Access Token having ads management permissions
Finally, you will be able to target your campaigns to the right audience in real time. If you need guidance for integration issues, feel free to contact me.