This means that if you change a headline, you can’t change anything else. Plus you have to make sure all other variables remain the same, like the mailing day or a war breaking out that has everybody watching CNN day and night or the President getting caught again with his drawers down or a hurricane hitting.
Frankly, most business people will just not go through the “detailitis” required to test - which is why it’s a very good idea to model proven promotions. And (more…)
