Making sure different versions of your domain name sends users to the one domain is massively important for a number of reasons. It is important for search engines whilst indexing so they know that www.analyticsseo.com is the same as http://analyticsseo.com and not duplicate content. You don’t want Google to think they are two different sites unless they really are. Try adding a 301 redirect so that the non-www version of your domain is redirected to the www version or vice versa.
It will also guard against diluting your inbound links as they will all be going to one domain rather than split between a number of different URLs. Use a 301 redirect rather than a canonical URL tag as it tells search engines that multiple pages should be considered as one, but different to a 301 redirect, does not actually redirect visitors to the new URL.