What do you expect?
The next time you create a new, exciting, cutting edge advertising campaign, take out a note card and write down the promise that you have created for the customer.
What are you saying the customer is going to get out of the experience if they do what you want them to?
Ok, now set the campaign aside.
Go and do business with the customer that you created the campaign for (make sure you take the card with you). Visit their store, go to their website, call them - whatever - interact with the client as a customers and see if you fulfill the promise you just offered up to the world on behalf of your client.
If you find exactly what you promised - home run. Place the media buy and let's sell some stuff?
If you didn't get what you said you would, you have a problem.
What if your advertising promises top notch service and a customer receives fair service?
What if hundreds respond to the campaign you created? Great - sales go up while the campaign is running!
The Client is happy.
Customers are disappointed. They do not become repeat customers. They do not respond to your advertising the next time it runs, and so the downward spiral begins.
Your advertising actually reduced sales in the long run because you prompted trial and offered a promise that wasn't delivered.
Uh! Oh! - effective advertising actually reducing sales.
Now that's a point to ponder.