The primary determining factors in the amount of shoplifting occurring in a shop are (1) the type of goods being sold, (2) sales policy, (3) the availability of staff, (4) shop geography, (5) display features, and (6) the use of crime prevention devices. In the development of anti-shoplifting devices and activities, the use of deterrents does not prevent theft or apprehend thieves, but they do discourage theft. Deterrents include posters warning about the consequences of shoplifting and appealing to persons' consciences, community campaigns against shoplifting, and the use of mirrors and other visible indications that a store is committed to countering shoplifting. Prevention devices or practices have a more directly preventive intent than do deterrents. They may include locks on showcases, chains on merchandise, electronic tags, corrals which funnel customers through check-out points, and pickup counters which limit the amount of merchandise accessible to customers. Apprehension activities or methods are designed to catch the thief after the fact. They include the use of plainclothes detectives, observation booths, monitored television, and similar devices.