The number and success of radio stations are strongly linked to station format. Listener demographics are linked to the station formats. Thus, separating the effect of station format from listener demographics is difficult. The bigger formats are country, oldies, and news/talk in terms of both number of stations and total audience. Stations with formats that attract certain listening groups (such as adult contemporary and oldies) tend to have a high ratio of revenue to audience. Stations that include the station name in their format tend to be the more successful stations in terms of size of audience and revenue. Although many stations include their format as part of the station name, and format has a strong influence on the success of a station, very few listeners write station format in their diary entries. One could conjecture from the data that the station format attracts its listeners, but the listeners rarely identify the station by format.