I've never done FB ads for my DJ work (since I work for a corporate franchise company) but I have for my playwrighting work (I've mentioned this before). I've ran ads for my dramatic podcast productions and my actual in theater productions. My last show, I ran 3 ads, and did a very narrow target audience. 3 ads with a total of around $50 spent over a week period, a reach of 5,876 people. That was with a very narrow reach. What I did was set two ads the same day, the third ad a day or two later. I set two of the ads to run all the time and a third ad to only run different hours. You might look at when peak times when people are)active on Facebook (IIRC I set mine for 7-9am, 11am-1pm, 5-10pm). I believe I cross posted my ads to Instagram (but I could be wrong, I know I thought about it, pretty sure I did) and you might look into Twitter ads.
Let me give you a real life example of the effectiveness of ads. A friend of mine does an interview style podcast. A couple of years ago, she started doing a semi-regular feature where instead of an interview that week, we'd present a live "radio play". Playwrights send in plays, we rehearse, and perform live. We have actors from all over the world; professional and amateur. No one gets paid. In November of 2015 my show went live, I spent $10 on Twitter and got around 3,000 impressions and 40 Tweet engagements. I ran one Facebook ad, day of show, $15 spent, around 1,200 impressions and 26 engagements. Again very targeted audiences. At last count, this particular podcast episode had been downloaded around 3-4 million times. Now granted, the host/producer has a nice following herself and many of the actors posted on Facebook, we did an episode of the podcast the week before which was an interview, but in the end, we ended up being one of her top 10 most popular episodes of the year. So I can't say it was JUST my Twitter and Facebook ads (I also bombarded Facebook and Twitter with targeted hashtags and scheduled posts every half hour) but I think it was a big part of it because I was the only playwright to spend money on ads promoting a show this past season and my show was the only play to break into the "million plus download" club.
Bonus, you can also usually get like $10 off future ads, so look for those offers.