Have you ever chosen a website with beautiful design and trusted that the people providing the services there were more competent than another less organized and poorly designed website? And was it so?
There is something about great web design that makes us feel like we can trust that product or service. However sometimes great design might not support a great service, but our mind thinks it otherwise. It's a "thing" we as babies do: prefer the symmetrical and beautiful over the asymmetrical. And now as adults our mind is the same. Countless times I chose a medical website with beautiful design over another with dark colors, or a delivery service with funny logos and good organization over other too difficult. Of course there are quite a number of elements in websites that influence our choices, however today we are talking about design aesthetics on the web and how this influences our cognition, affect (feeling) and associations (see below).
This refers to the matter of understanding. Test and check these three:
Is your message and your interface easily understood by your users?
The so-called "perceived affordances". In web design there are some standards of how a user can and should interact with an object or an action (think swiping or scrolling). Do you have those in the clear? Good.
Gestalt principles - referring to how elements for design are aligned in order to not confuse the user (read this article to find out more).
If your product was a person, how would you describe it? The "personality" you give your product greatly influences our perceptions of it. Think about how easily we form a first impression about a person we've just met - the same on the web. We do judge a book by its covers. Give your product or website a personality. Take into consideration these (list from "Seductive Interaction Design):
People identify with (or avoid) certain personalities.
Trust is related to personality.
Perception and expectations are linked with personality.
Consumers choose products that are an extension of themselves.
We treat sufficiently advanced technology as though it were human.
For example, Mailchimp with it's monkey mascot has a funny and still professional feel to it. You can infer whatever personality you like to your website, as long as it shows a bit of you and you target audience (if funny, do your users get the jokes, relative to their age, interests, motivations?). It's easier to design something by starting with a design persona.
We form cognitive and emotional attachments to a product but also if it reminds us of something familiar (sometimes unconsciously) it seems to stick to our mind. Author of "Seductive Interaction Design" gives this example:
He comments "But this association extended to something else that, to my knowledge, no one else has commented on: the packaging. Do the arrows and shades of green bring to mind a particular brand of gum?"
So yes, beautiful design and attractive systems (offline or online) are perceived to work better. Keep it nice and tidy guys!