Mere-Exposure Effect
Psychological phenomenon by which people tend to develop a preference for things merely because they are familiar with them. Doing something many times makes us believe that we are good at it - independent of our actual skill. Used in advertising - seeing the advertisement of a brand multiple times will make us like it more.
Consequences
The mere-exposure effect exists in most areas of human decision-making. For example, many stock traders tend to invest in securities of domestic companies merely because they are more familiar with them, even though international markets offer similar or better alternatives.