When you run a Growth campaign, you unlock the potential to rapidly expand your audience. Most creators see dramatic increases in Instagram followers, Spotify followers, YouTube fans—the list goes on and on. While seeing those numbers soar is definitely a great feeling, analyzing those numbers—tracking the performance of your Growth campaigns—is the way to gain valuable insights into your audience and your marketing investment. In this article, we’ll examine two critical performance metrics: cost-per-click (CPC) and cost-per-follower (CPF). We’ll look at how they’re calculated and why they matter; plus, we’ll preempt common questions.