I think that's a great point, and definitely hard for a huge company like P&G. But for a small company, it can be easier, because when your volumes are low enough, it's often very easy to directly see sales uplift in your top line numbers when you run the ad. If I normally get 20 orders a day, I run an ad and get 40, then the ad budget runs out and I'm back to a steady 20, I'm not too worried about cannibalization.
For a huge company it's even harder. I think the internet ads serve partly the same as news paper ads. There is no click through for them either. Actual paper ones.
We have a couple different phone numbers exclusively for advertising campaigns. We can note the line it came on when receiving the call. We're a small-mid business, so I assume larger businesses have budgets for a lot more ways to track printed media advertising that isn't too obtrusive.
