Like most media outlets radio stations generate the majority of there profits through advertising on their airwaves. The different times available for companies to feature an ad are called spots. Spots are sold for different prices depending on the size of the audience at a given time. For example an ad featured in a spot during the morning rush hour is considerably more expensive than an ad featured in a spot in the late evening. This is because the ad will reach significantly more people during the morning rush, creating a demand. There is only a certain amount of time during rush hour, limiting the supply, thus driving up cost. But aside from the fundamentals concerning the driving forces behind pricing, radio advertising has proven to be very beneficial to both the service provider and the customer.