The Consequences of Running Tests Longer

People are now much more aware about external validity concerns, so they're running tests for longer. The distribution of lift estimates is such that a lot of the effects that you might expect from your tests is very small,. Which means you need to prepare to wait for longer to be able to detect them. But it's also important to do so, because otherwise, you're missing on this small incremental steps which would build a good product over time.