A 1990 review of 72 such studies by Weinberger and Hardaway found significant effects and in some cases behavioral outcomes. However, these studies are difficult to conduct, don't always work, and sometimes supraliminal messages work better. The effects tend to be temporary. But Is the influence really greater because it is not noticed. Why does belief in subliminal persuasion persist.
People often mistake presence for effect.
There is little or no evidence of subliminal effects on attitude or motivation.