Rating subdomains

As explained on WOT's main Support page section: Rating Subdomains.

How does the system rate subdomains?

Subdomains are often used with free hosting and social networking sites, for example. The WOT community can rate subdomains in exactly the same way as the members rate other domains. If WOT doesn’t have enough ratings for a specific subdomain, the subdomain inherits the parent domain's reputation. Once the system considers there to be enough supporting evidence to calculate a separate reputation for the subdomain, WOT will start to use it.

Similarly, the reputation of each subdomain contributes to the parent domain's reputation. If a domain has lots of untrustworthy subdomains, its reputation will suffer, and, therefore, the reputation of any new subdomains will suffer as well. We designed this logic within the WOT system to model the way trust works in real life.

The www subdomain

... the owner of the domain also controls the www subdomain. Since the www subdomain is commonly used as an alias for the main website hosted on the domain, we believe they should also share the reputation.

- Sami 27 May 2009

forum discussion: subdomain question - "www."

note:

If the subdomain contains "www" plus a string of integers such as: www1, www2, www123, www4321, WOT considers them to be equal to the parent domain as long as both of these conditions are true:

1. the host name matches the regular expression

   /^www(\d[^\.]*)?\..+\..+$/i

2. the parent domain is not a TLD (or an eTLD)

Multi-level subdomains

When a subdomain inherits the parent domain's reputation, the confidence level decreases to half on each hierarchy level. Depending on how reliable the parent domain's reputation is, at some point the confidence for the inherited reputation falls below the minimum threshold and the subdomain is shown as unrated. Here's an example, look at the confidence indicators:

http://www.google.com
http://www.1l.google.com
http://www.2.1l.google.com
http://www.3.2.1l.google.com
http://www.4.3.2.1l.google.com
http://www.5.4.3.2.1l.google.com
http://www.6.5.4.3.2.1l.google.com

So, currently the 6th level subdomains of google.com have no reputation in any rating component. If one of the parents lower in the hierarchy later receives ratings and gets a reputation of its own, the higher level subdomains will inherit its reputation instead.

— Sami

Shared domains

If your site is hosted on a shared domain, such as blogspot.com or wordpress.com it used to inherit the parent domain's reputation, but starting 27 May 2013, these domains are treated as effective top level domains (eTLDs) so these subdomains each have to earn their own reputation, if no reputation exists they will display the unrated symbol:

— Sami

For more reference, please read these blog posts:

• The Neighbourhood
• How many sites do we know?

  discusses how reputations traverse the domain hierarchy

see also: Shared domains