I think the most important one was people say one thing and do another. This is true both from the sales perspective and a user experience/user testing perspective. Here are a few examples

- People wanted cheaper mobile app analytics, but they wanted a brand they could trust - People wanted a lot of insights, but they would never understand most of the charts

On the whole, products which are used during firefighting are are hard products to sell and differentiate on. Google/Fb/Amazon could build a product with 10% of the feature coverage and yet own the market.

I recently wrote a bunch of things I learned here -> https://ravivyas.com/2018/09/03/mistakes-to-avoid-when-scali...