Drug company manager: Our newest product is just not selling.
Conclusion
We should try a new marketing campaign.
Evidence
Our new product isn't selling and a new marketing campaign would have a chance of saving it.
Evaluation
Given that the new marketing campaign has a chance of saving the new product, how could we argue that we shouldn't try the new marketing campaign?
Maybe there are other options that are much better than the marketing campaign? Maybe, even though the marketing campaign has a chance, it's a very small chance and not worth the time / money / effort? Maybe the possible good we would get out of the marketing campaign saving the new product is outweighed by whatever possible bad stuff it could trigger.
Goal
Find a reason not to do the new marketing campaign.