Consider a car used by a company which has "advertising" printed on it regarding the actual company.
How should domains be displayed on such a car? Is there any research regarding this? With a wide target-audience; how to ensure that they userstand that it's a domain?
www.domain.com
domain.com
DOMAIN.COM
I'm looking for answers for richer countries, not developing ones.
For most people, domain.com is as clear as www.domain.com, and so the preference depends on the designer (although I prefer domain.com)
However, naked domains (i.e. domain.com) and the www version are not always synonymous. First make sure that the naked version works.
Don't just use the naked version without first checking.
"http://domain.com" is unambiguously a website. "www.domain.com" is equally clear but technically not necessarily a website. "domain.com" is likely a website. "go.to" (Tongan TLD) is recognized by the internet savvy as a domain name and likely a website, but many people might miss that meaning.
I'd be inclined to use "http://" or "www." as a prefix to reinforce that it's a web site, even if it ends in ".com". Human languages are full of redundancies that make comprehension faster and easier, and I view that prefix (http:// or www) as similar redundancy that indicates at the briefest glance that it's a website.
edit add: and use all lowercase letters.
I think most people nowadays understand it by first-level domain name (i.e. .com or .net, etc) so I believe you may drop the www. part.
It's usually best to follow popular convention. In my area, the print marketing materials I've seen almost always include the www and usually exclude the http/https protocol.
Though, if space is an issue, I would expect most anyone with internet access to understand domain.com as well.
And I can't think of a marketing scenario in which the protocol prefix would be necessary. Leave it off. It's ugly.
Using www. or not in front of the domain could depend on your audience. To be safe, prepend the domain with www. so there is no doubt.
I would recommend all lower-case for esthetics. I have made content for many large companies in the past involving their domain and so far there has been no exception to the domain being lower case (Europe, it may be different other places).
Consider a car used by a company which has "advertising" printed on it regarding the actual company.
In addition to this, why not add a QR code?
Keep the traditional (understandable by grand-paps and non-technical audience) www.domain.com and add a QR-code for the more young, modern and enthusiastic audiences. With a QR code you can just point your mobile camera at it and go directly to the site it embeds (example below goes to wikipedia.org).
