I was on a video call with someone who is developing a good software product and they were not sure what business model / pricing strategy to use.

I am no expert in this, having no successful online businesses of my own, but I did remember reading an amazing book on the topic, called Business Model Generation. It seemed to provide a pretty complete guide on various business models.

The one thing I heavily used form the book was the Business Model Canvas. I use this tool to validate whether an idea is worth pursuing, because it has you list out everything that a certain business should involve in order to work and make money.

Have at it!