What do you guys think? Does it matter? Companies seem to handle it about 50% this way and 50% that way:<p><pre><code> twitter.com
www.airbnb.com
balsamiq.com
www.reddit.com
jsfiddle.net
...</code></pre>
I generally go without the www personally.<p>There is no SEO difference that I am aware of as long as you do proper redirects. One person pointed out to me that with a naked domain you lose the ability to scope cookies to the www hostname. But does that really matter? Doesn't to me, at least yet.<p>In the past, I know some DNS providers had issues with naked domains and redirects, so that may come into play if you have one of those providers. By now though, I would think they all support it properly.
The only important part (in terms of SEO) is that you pick one and stick with it. Setup a 301 redirect from the other one. Google interprets the www as different sub domains, and therefore different domains. (Search for "one way street" SEO theory -- top level domain can pass juice down, but not vice versa. That's why places like hubspot don't suffer from spammy subdomains)
There are two advantages to using www.* for a main web site.<p>1. As luaks points out, you can use a CNAME to alias just the webserver, without affecting MX configuration, etc.<p>2. You can have use alternate subdomains (like static.example.com or cdn.example.com) for handling static content and prevent cookies from being sent with those HTTP requests. This is a slight performance gain.
For a new project it will probably not matter at all.
The thing with www though is, that you can use CNAMEs for aliasing on the DNS level. Technically you can use CNAMEs on domain root to alias the whole domain to another one, thus leading to you not being able to add other records (for example MX) to this domain, which you probably want to do.
Hm, I like subdomains more than url stubs. I like more 'atmosx.github.com' than 'github.com/atmosx'. So I like having mail.domain.com, www.domain.com, ftp.domain.com, shop.domain.com, blog.domain.com, etc.<p>But I don't think it's such a big deal. Especially if you're not planning to use all these subdomains... Then <a href="http://domain.com" rel="nofollow">http://domain.com</a> is more than fine, as long as you setup a rdr.
I say without the www looks more appealing.<p>The www was included for a time when browsers were not the primary way people used the internet, and so you needed to specify www the way you specify, say, ftp. Nowadays everyone assumes something.com means port 80.<p>As long as you redirect www to @ you should be fine for SEO, right?
It's slightly more convenient to use www for the reasons luaks points out, but it's more about what you prefer.<p>For SEO just ensure you do 301 redirects from your non-preferred one to your preferred one (same goes with HTTP and HTTPS if that is a factor for you).
Check out <a href="http://www.yes-www.org/why-use-www/" rel="nofollow">http://www.yes-www.org/why-use-www/</a> if you're not aware of it already. I agree with all the points raised there and would use www myself.