FaceBook's algorithms are incredibly good, they have also been investing massively in improving the ads platform with many new features, any many more rolling out.

Run a Facebook lookalike campaign to reach an audience with similar interests, buying trends and habit to your target audience. I suggest keeping an eye on this closely, I’ve had this work VERY well on one of my businesses, but on another it completely failed (I believe because we had a wide target audience) so make sure the results are good before you scale the ads.