When working with their websites many companies set up micro sites with sub-domains or entirely new domains such as www.yourcompany.com for the main site and http://campaign.yourcompany.com for the micro site or www.campaigncompany.com as a stand alone website address. This may seem like a good idea for making the content in each of your campaign stand out as a separate offer but in the SEO world this isn't a good idea.

When Search Engines view your site they use the website address to identify the site as a stand alone entity, so they will see www.yourcompany.com and www.yourcompany.com/products as part of the same site. However when they see www.campaigncompany.com or http://campaign.yourcompany.com they view this as a separate website, and won't rank the copy in with the rest of your site.

This means that when you are trying to prove that your site should appear highly in search results for your products, your message is diluted across all the campaign micro sites. This is particularly true if the micro site uses some of the same keywords as the main site. Search Engines are looking for relevancy for your keywords and the more content they see on the main site relating to each keyword the better you will rank. So, splitting your content out into multiple micro sites reduces this relevancy - reducing the chances for you getting the traffic you want to your new campaign.

So when you come to launch your next campaign consider the impact of rolling out a new domain to the success of your website and search engine optimisation!