Being an Indy Coder means you don't have unlimited resources. There are only so many hours in the day for working, learning, and marketing. Don't waste hours learning things that you can't or won't leverage other ways.
But learning new things is always useful, right?
No. Not really. Here's an example.
A couple of years ago I invested a LOT of time learning how to interact with a third party enterprise CRM. It was a request from a regular customer, and meant 100s of hours of business for me.
But looking back, it wasn't a very smart decision. Customers of ...