It’s tempting to have a unique domain name for a special event or sale, and have that point to the landing page of your site. However… that may not be the best idea from an SEO point of view. How come?
Let’s explain this with an example: you have two domains leading to the same site: yourbusiness.com and yourevent.com. Analytics crawlers will crawl both sites individually- not as one single site. There is more than one problem with this.
Duplicate Content. Google has something called the “Duplicate Content Penalty”. Because crawlers treat both domains as separate sites, anything that they find on the second domain will be treated as duplicate content and will be penalized in search engine results.
Devalued Domains. Analytics will automatically choose a canonical (preferred) version of each crawled page, and these may or may not be on the same domain. If they are NOT on the same domain, it can seriously hurt your search engine rankings.
Diluted Links. If you are running links to more than one domain that is pointing to the same content, each site will only get credit for half of its inbound links… and inbound links are key for search engine ranking.
When putting on a special event or promotion, the best way to have a specific domain for use is through a 301 redirect. A 301 redirect is a permanent redirect which passes almost all of the recognition and ranking power to the redirected page. Contact your webmaster for more information.