Ask How long should a business wait before judging whether a new ad campaign is working?

[Newman]

A new ad campaign needs a bit of patience before anyone can judge it fairly. Ads usually need time to reach enough people and collect enough data before the numbers make real sense. Judging too early, like after one or two days, can give a wrong picture of what is really happening. Most businesses wait at least one or two weeks before drawing conclusions. What do you think is a fair amount of time to test a new ad campaign before deciding if it works?