Television advertising reaches large audiences and uses picture, print, sound, and motion; its disadvantages, however, are that it is expensive and perishable. Radio advertising is inexpensive and can be placed quickly, but it has no visual element and is perishable. Magazine advertising can target specific audiences and can convey complex information, but it takes a long time to place the ad and is relatively expensive. Newspapers provide excellent coverage of local markets and can be changed quickly, but they have a short life span and poor color. Yellow pages advertising has a long use period and is available 24 hours per day; its disadvantages, however, are that there is a proliferation of directories and they cannot be updated frequently. Internet advertising can be interactive, but its effectiveness is difficult to measure. Outdoor advertising provides repeat exposures, but its message must be very short and simple. Direct mail can be targeted at very selective audiences, but its cost per contact is high.