This is an overview of spot lengths that ran, according to the spot logs submitted by your broadcasters. By default, the spot lengths are ranked by cost per visitor to your website. If you also have tracking numbers associated with your broadcast advertising, you can track cost per phone call by choosing the Phone Calls button in the upper left of the graph.
As you roll over the data for each spot length, you will see the number of spots aired, the number of visits to your website after the spot aired, the cost per visitor, and the rate at which viewers respond to your spot. For instance, if your rate is .38 it means that for every 100 times your spot aired, 38 viewers visited your website.
The goal is to identify the spot lengths that offer a high ratio at a low cost per visit. By choosing the Index view in the upper right hand corner of the graph, you can see the relative efficiency of each spot length.