Domain Age: The age of your domain can have an appreciable impact on your domain rankings. In otherwords, the older a domain is, the more its search visibility by search engines on a particular niche.
Domain Registration Length: Domains registered for more than one year is an indication of domain legitimacy. Therefore, when a domain is registered for three, four years or beyond, it is then an indication that its contents are rich and valuable and the risk factor of it been a scam site is very low. So, webmasters wishing to rank high among search engines must ensure that their domains are registered for a considerable length of time of at least three years.
Appearance of Keyword As First Word on your Domain: When your main keyword appear as the first word on your domain, then that would be a boost for it in search engines as it would rank higher compared to keywords that appear at the middle or at the end of a domain.
Private Whois Info: Sites with private whois information may portend some signs of concealment and can compromise its search visibility as Google may assume it to be a scam site or having some malicious intent.
A Domain’s History Analysis: Google may reset your site’s history if it notices volatility in ownership or some other inconsistencies periodically. This reset can seriously compromise your site’s ranking as links pointing to your domain may be subverted.
EMD Effect: Exact Match Domain can positively or negatively affect your domain’s ranking. It the exact matched domain is a quality domain, then it would have a positive effect on your rankings. However, if it is from a low quality domain, your site may be hit by the continuously changing Google algorithm on EMDs.
Defaulting Whois Owner: If Google identifies that a certain site owner has been penalized previously, then it would scrutinize all other sites owned by that webmaster as it tries to identify if he is a spammer.
Country-TLD Extension: Having a top level domain extension for a particular country would boost your domain’s ranking for such a country. For instance country extensions such as .us, .uk, .ng, .za etc are unique country-TLD extensions.
Keyword Appearing in Sub-Domain: Keywords that appear in a sub-domain boosts ranking according to SEOMoz’s panel.