Designing a better onboarding flow

putting the screenshots of the workflow in a huge, horizontally scrolling google-drive hosted PNG is really obnoxious. Why not just put them in the article?

The author has the email marketeer's model of customer onboarding. - onboarding is complete when an email address has been captured. "We have you now!" The product is targets to spam, and the service provided is a loss leader for that.

There's a school of thought that onboarding is only complete when the user perceived that they are getting more value from the service than the effort they put in to use it. For some services, that's a long process. Github onboarding is complete only when the user has created a repository or made a change to some existing one. You don't need to be a Github user to read.

This is sometimes confused with customer retention. It's different. Customer retention is about keeping customers who fully completed onboarding. The signup that never did anything was never onboarded. (Also, it may just be a signup bot.) This is especially important to services which have a free and paid tier. Counting free customers too soon creates the illusion that there's a big customer base ready to be converted to pay. That pool may be much smaller than thought.