Psychology has a lot to do with marketing.  Marketers promote their products through various different ways to induce the mind of consumers in a way that they want to buy or promote their products.  Companies utilize some of the different disciplines within psychology, to induce how their potential consumers think and feel in order to make the decision to acquire their product.   It is a fundamental and important trait when it comes to marketing, because as entrepreneurs you want to ensure that you research your product enough to understand your target base and tailor the promotions of that product to those people so that they acquire that product.  For example, if I wanted to make an energy drink and young adults in college was one of my target bases, I would think a way to market my product in a way to attract that audience.  Maybe something like the color scheme, or a commercial or graphic that has younger adults consuming the product, in a medium where I know my base resides like social media.  Having a interdisciplinary mindset will go a long way for any entrepreneur, because you can use different disciplines to look at your business in different ways.