Customers will buy your products or services for both emotional and logical reasons.
Your marketing has many components, and each is suited to both emotional and logical buying triggers. But, these components are often more well-suited to one or the other.
Design Layout: Logic. You need a logical design layout to make your marketing easy to process and to make it make sense.
Color Palette: Emotion. People make strong emotional connections with certain colors – they'll evoke a feeling or a memory for them. Play off some of the most common color meanings to get the most bang from your color palette.
Descriptive/ "Marketing" Text: Emotion. Think of the short text or voice script in commercials or print ads. This sort of text plays to the buyer's emotions – tries to create a scene, feeling, or to describe the benefits of whatever it is that you're selling.
Factual Text: Logic. Most longer marketing pieces – sales sheets, web pages, brochures, etc. – have to have some sort of factual text. Information about the features of your product
Logo: A good logo appeals to both. Emotional is handled by the icon (in the way that it's drawn) and color palette. And logical is handled by the icon (which needs to make sense) and the company name.
Keeping these roles in mind can help you to create the most effective design and marketing materials.