According to ebizMBA.com Facebook hands down is the most used social media platform. That being the case Facebook does offer many great ways to advertise. You will have to create a few additional free accounts with Facebook in order to advertise but hey its free.
Facebook advertising allows you to use an existing Facebook Post or you can upload an ad image of your own and then target audiences specifically. Then if that wasn’t good enough you can go back and re-engage that same people who saw you ad or video and hit them up again. Now here is the genius part. You can create a duplicate look a like audience based on the people who already viewed your ad. Facebook has all the data so they know how to target people i the same niche you originally targeted.
There is much more detail and steps to executing on this but at least you know that this is possible now. Isn’t it time to tell you agency that you want them to do this for you? Hope this helps.