|Mirror Site is a duplicate of a website at a separate URL. This allows websites to spread out the resource load on a server. Mirror Site is also built to improve the traffic. There may be a website of the company which may not be yielding the desired audience. Mirror site URL is created using name of the keyword phrase that represents the company product having high hit. All the traffic is generated on this mirror site and then it is redirected to the main company website.
Such mirror sites are specially designed for search engines considering a particular key phrase. The keywords placement in body text, alt tags and meta tags is where the expertise of an SEO is tested.