You can't effectively evaluate a strategy without knowing something about how it might be executed, and you can't develop an effective execution without first picking a strategy. How do we solve this dilemma? We "wash, rinse, repeat."
The first step is to throw everything into the wash. Using all available data, we develop alternative strategies and create preliminary executions of each. Next we rinse out the best strategy by testing those preliminary executions. Finally, utilizing what we've learned, we repeat the creative phase again, this time zeroing in on what is now the proven winning strategy.
Sure, we use a little shampoo -- but it's worth it. Because if your ads really shine, so will your bottom line.