Is the call for action attractive enough? Does it address your target audience's need? this will make your ad successful to the people you want to reach and this is how they will remember your brand as well as the ad.
Most of the time, the only reason you would read a copy is because the Ad is placed and designed properly to attract a viewer. I'm gonna have to say placement and design.
A radio or tv ad has to be attractive, concise and straight to the point. Knowing your target audience well helps a lot, and makes the customized multimedia packaging of your idea more appealing and, eventually, the delivery of your message much easier.
