An excerpt from the book: Design for Hackers by David Kadavy

“In our cluttered world, full of disparate pieces of information all commanding our attention, the attention of your audience is at a premium… Making your work visually interesting ensures that your message is taken more seriously and gets this ever more precious attention. If you have a visually interesting interface on your application, customers will choose your product over one with equal features and pricing that is less visually interesting. In some cases, they’ll pay more for the perceived extra value created by a more visually engaging interface.”