When i stared blogging in 2008, i knew nothing about Canonical Urls and whether there is any importance of following the Canonical Url rules. I that discovered that Google is really serious serious about the canonical Url.
Well, this is about having a www. at the beginning of your domain name or the choice to ignore it. This is something which people and webmasters ignore from the beginning yet it can have some negative or positive implications depending on the choice made.
Bad Or Good
From experience i have discover that deciding to use the www is not evil, on the other hand, ignoring the www is also not evil. The only problem comes when you you mix the two. You have to make a choice from the beginning on which canonical url you are going to use, whether one with a www or one without a www
Google and other search engines will treat a url with a www different from that without a www. For example, the urls below are very different in search engines will treat these urls as different.
The real problem
The major problem will come with mixing up your domain SEO ranking, if you use www to link to your domain and avoid it in other links, then you rank will be split between those domain. That is why i said that it would be good to know from the beginning which canonical url you will be using
If you use www and in other cases you avoid it, search engines will treat your content as duplicate and you will be headed for a search engine ban. Those who have ever been banned by search engines can understand the real pain of being left without traffic.
What i prefer
Personally, i would prefer a domain with a www at the beginning, it is the most widely popular way of writing domain names, many webmaster also use to while linking to a website.
If you neglect using the www tag, you might end up with lots of DNS problems. It might also create problems with your mail, rss and FTP access.
Using www was also the ‘standard’ way of indicating an internet server as opposed to a corporate intranet server for many years
All in all, either ways can work. It normally comes down to the marketing side though some technicalities might arise when using a url without www