Part of your on-line marketing efforts should be to make sure that you add your site to directories/websites to increase your visibility and to benefit Search Engines. When the Search Engines are indexing your website they will also be looking to see in how many other places your domain name appears. Using their internal algorithms they can the calculate the weight of your site and therefore the importance of your site and ultimately your ranking position.

Shameless plug : Twist Systems run our own directory which is super SEO friendly and its free. Sorry but at the moment it only covers Wales.

http://www.twistlocal.co.uk

 http://www.twistlocal.co.uk/create-my-account/Ammanford.aspx

(note there are many other factors which also affect positioning this is just one area. )