Some research by clinical psychologists suggests that subliminal messages can influence people under very specific conditions, though it is doubtful that these techniques would be of much use in most marketing contexts. For this kind of message to have a prayer of working, an advertiser has to tailor it specifically to an individual rather than the mass messages suitable for the general public.61 The stimulus should also be as close to the liminal threshold as possible. Here are other discouraging factors: