Success means something different for everyone.
There is not a right or wrong when it comes to measuring success.
If you currently have 10 downloads and you have a goal of 100…PERFECT! If you have 1000 downloads and you have a goals of 5000… PERFECT! The goal is up to you.
Start with the end in mind. If you need 100 downloads, figure out how you get one and duplicate. If you posted your podcast on your personal Facebook page and 5 people listened. Do it again every time you have a new episode. If you like to look at the numbers, a weekly episode +5 new downloads = 20 weeks.
If you want to leverage your efforts, become more intentional. Create a Facebook business page, and a landing page that will capture emails. So now when you share your podcast, you add it to your website, copy the website link to your Facebook page and then share your business Facebook page with your personal one. The chances are you will triple your efforts. So now your 5 new downloads is actually 15 each week= 6 weeks. That is a huge difference.
Know you goal. Start with the end in mind. Use measurable efforts to determine how much energy you can put into managing your goals.