Does Google prefer shorter domain names

A few weeks ago I tweaked some of the settings on my site – particularly in the .htaccess file which controls URL rediretions and obviously I made a mistake somewhere because now in Google’s search engine results page (SERPs) my website URL now shows up as www.mj7.co.uk rather than www.mjdigital.co.uk – see below:

Google search for mjdigital

As soon as I saw it my immediate thought was to fix the error and ensure the mj7.co.uk domain name is only used for my minilinks – but then it got me thinking – why did Google use this domain name instead of my mjdigital.co.uk – here are a few extra thoughts:

1. I only use mj7.co.uk when sending/using minilinks (shortened urls that allow me to handle different content in different ways)
2. I have never put a www infront of the mj7 domain – yet it is shown in the SERPs with a www
3. mjdigital.co.uk has been pointing to my webspace since May 2007 – I bought mj7.co.uk at the start of 2009 and only recently started using it
4. I use a <link rel=”canonical” href=”http://www.mjdigital.co.uk/” /> tag to attribute the content to mjdigital.co.uk and avoid a penalty for duplicate content
5. The site is branded MJDIGITAL and the content is related to MJDIGITAL

So, with everything I know about SEO and Google’s preference of domain usage I would have assumed that Google would continue to use my mjdigital.co.uk domain – but obviously this is not the case.

This leaves me with the only thought that Google prefers shorter domain names.

Now, with that thought in my head I wondered if it would have any effect on placement – whether (theoretically) two identical sites would rank differently if one had a short domain name and the other a longer one? What are the rammifications of this – does this trend affect full URLs?

What are your thoughts?

I would be really interested to see if anyone knows the answer to this question – please post your comments below or tweet me @mjdigital