"Lesson learned: always test higher prices. I didn’t bother with the setup required to run simultaneous A/B tests. I just raised prices and watched what happened."

Not enough startups do this on a regular basis. They're too worried about losing clients. If you don't reinforce your value proposition on a regular basis by adding features, you will lose customer regardless.

With several of my side projects, I would add a new feature, then raise prices for new customers. At the same time, clients who renewed (I used a subscription based model) would get a discount. It was like magic. More people wanted in earlier, instead of waiting for a more mature, more expensive product. They gladly paid a lower monthly fee up front, in order to avoid the increase in price later on.