If you advertise your business on the radio, try having your ads run between the hours of 6:00 AM and 10:00 AM, or 3:00 PM and 7:00 PM.  Popular syndicated radio shows are scheduled during these times, so you’ll get a loyal audience that’s listening to their favorite celebrities while they’re driving to and from work.  That’s a captive audience!  Ads run during these times tend to be a bit pricier, but it’s because it’s easier for the customer to track how the ads are running, since there’s a relatively small block of time in which the ads will run.  Remember as you create your ad schedule that you’re NOT buying ads.  You’re creating a customer base.  Your competition is fighting hard for your customers’ attention.  You need to reach your public FIRST.