Following up to Jennifer's 'embrace call tracking' post, it really is the only true way to measure how advertising is working for your business. The only  exception would be if there is a 'call to action' attached to the ad such as a coupon, or an offer 'with the mention of this ad'. Well, I can't tell you how many times I personally forget to bring the coupon to a certain business; although it may have drawn me in, it does not necessarily mean that I am going to leave simply because I forgot to bring it. I just figure that I will save it for the next time. Even if I mention the forgotten coupon, no one  asks me where the coupon came from. Time and time again when I ask an advertiser how they are measuring the effectiveness of their ad, the standard answer is 'we ask how they heard about us'. The kiss of death. Even if they do ask, is anyone really going to remember which publication they learned about the business in? Several Hollywood businesses advertise in multiple publications so who really knows which one the consumer is going to mention. Perhaps the wrong one. Be proactive and learn about call tracking and ask about other ways that we can help you get the most out of your advertising dollars.