Does is matter whether you choose to call your site

http://www.searchengineworkshops.co.uk

or

http://searchengineworkshops.co.uk

The short answer is no – Google and the other search engines have no preference.  But the important thing is that you decide which to use, stick to it and then use a 301 to redirect the other version to the chosen version.

So if I decide to call myself

http://www.searchengineworkshops.co.uk

then I must put a 301 redirect on

http://searchengineworkshops.co.uk

to redirect it to the www version.

Historically it mattered that the www was there but for many years now it has been redundant so it really is a matter of choice which you use.  On the plus side for the www campaigners is that generally it’s what visitors expect to see and are more likely to use the www in any link they make to your site (though the 301 should pass all the link juice on if you are using the non www domain name).

For the non www campaigners, it means typing four fewer characters that don’t do anything.

The only thing that matters is that you are consistent and use a 301 redirect.

I do have one client who uses the non www domain name for their internal use and uses a robots.txt file to exclude it from the search engines.  This is a perfectly good way of dealing with the problem albeit an unusual one.

For more information, there is a very good post written by canonicalseo

Trailing slashes in SEO

A separate but related issue is the use of trailing slashes.  Many sites are now built without page extensions, so instead of

http://www.searchengineworkshops.co.uk/in-house-training.html

the URL is built as

http://www.searchengineworkshops.co.uk/in-house-training

except that Google can pick up

http://www.searchengineworkshops.co.uk/in-house-training

as separate pages

http://www.searchengineworkshops.co.uk/in-house-training/

which all gets very messy.