The general consensus right now is that if your show doesn't have 30,000 - 50,000 downloads per month, you can't get any sponsor to look at you seriously. To really get the big advertisers (MailChimp, Squarespace) you need 50,000 downloads per episode.

If you're looking to earn an income from a podcast with smaller download numbers, here's what's worked for me.

Background -- my podcasts (MegaMaker, Product People) focus on a very specific niche. They're for software developers, designers, and other makers who want to launch their own software products.

How many of my listeners might support my show?

What percentage of my listeners might support the show? Is it 3%, 5%, 10%?

One way to determine this is to figure out the amount of "purchasing intent" your listeners have.

For example, the book I just released had an email list where people get notified about the launch. Here's what the math looks like:

1,359 people on the launch list

663 of those people bought

= 49% conversion rate

Now, let's compare that conversion rate to my overall list:

12,703 people on my mailing list

674 of those people bought

= 5% conversion rate

So 5% of my big list bought. But when I narrow it down to the launch list, the % is much higher (49%).

The podcaster's sales funnel looks like this: