Psychology has a lot to do with marketing. In order to be successful at marketing, the entrepreneur must appeal to their audience; and in order to do so, they must get inside of their head. If people feel like a product or an idea “connects” with them, then they may feel obligated to buy or use the product. When trying to market a product it is important to consider how impulsive people can be, how colors make people feel, how the brain processes images, how certain phrases can affect people, and how purchases are typically based off of emotion. For example, when thinking of phrases and words to associate with the product, it is important to think about which words make it “feel” more authentic and trustworthy. Even if the product is good, if the marketing is bad people would not be as interesting in the product. The same thing also applies to the visual aspect of marketing. People are known to process images faster than words. Statistically, images make the product more engaging for the consumers. This shows how much the brain and how people think, affect marketing techniques. 

Source: http://www.wsistarwebsolutions.com/_blog/Blog/post/the-relationship-between-psychology-and-marketing/