They will carry your message, right or wrong. If you want to make a change in your business, that may be tough. It's not easy to change a mind that's already made up. Broken record time again. People do not buy products based on comparing the facts and making a logical decision.
People buy products based on emotion and create a logical argument for that position.
If you aren't reaching your target market you are wasting your advertising dollars. How often will be determined by the success of your ads and your budget. If your plan is done correctly then advertising should pay for itself. It should produce more income than it costs. If it is done incorrectly you won't be able to do it for long because it becomes an expense.