M.

All comes from the famous story. And not many knows the full story including myself, until now.

The correlation was discovered with no statistical method or modelling. All it was is that run the SQL query and then hey, something interesting. This is not easily copied to other stores as people are different.

Things would not change - test your hypothesis and test it live then prove/disapprove it. Least take the feedback into the model (thought process) to fine tune it.