In a happy room, most people get happy. In a sad room, most people get sad.
People conform to the emotions of the group or environment.
That is why casinos and top retail outlets try so hard to create an emotional atmosphere of carefree spending or something similar that will cause emotions that lead to spending. Have a look at your site. A site's text, prose, colours, graphics and quality can make or break an online business just from the emotional angle. Same thing with banners and other ads that you do. Even if you go out to buy a boomerang, the principle is the same.