On a tangential note, how many downloads a day do we need to hit $30K, enough to barely survive in America?

Let's do some rough math. These numbers are based on when I worked at a company for two years on an app with many many thousands of downloads and relatively high usage time per session and high repeat usage value (think more a daily journal app, less a pick-up-and-drop game app).

To simplify numbers initially:

Given: 100 downloads a day

Given: 3% conversion rate to Daily Active Users

-> DAU per year = 100 dl * .03 conversion * 365 days = 1095 DAU / year

We can imagine the user count as the area under the constant graph y=x because user count steadily increases. Then, the average DAU is the top half of the triangle cut out and put upside down on top of the early part of the graph, making a rectangle. This makes the average DAU half that of the DAU by end-of-year.

-> Average DAU throughout the year = 1095 / 2 = 550 avg. DAU

Given: $0.015 daily per user

-> Revenue per year = 550 avg. DAU * $0.015 * 365 days = $3010

With 100 downloads a day, we should expect $3,000 a year. That means we need to aim for 1000 downloads a day to hit our target $30,000 a year.

This is one data point for a high-usage, high-repeat-user app. This may be a bit simplified, but it should be in the ballpark of the numbers we need to hit to survive for an indie developer.