Last week I wrote an article for The SEM Post on the hazards of zombie sub-domains and how your very own site could be affected without you being the wiser. I also used an example of Houzz.com which is the 177th most trafficked website in the USA yet it is suffering from zombie sub-domains; it can truly happen to anyone.
What follows is the introduction and a link to the full article here:
Google dislikes spending precious resources indexing web content on your site that is of no consequence to itself or its users. Inconsequential web content can be present in the form of duplicated pages and irrelevant or repetitive and/or thin text. Even worse, it is a waste of Google’s crawl budget on your site and such content will delay the indexing of legitimate content. In this case, however, the offense is greater than usual because we are dealing with unlimited duplicate versions of a website triggered by improperly installed DNS wildcards; I none to fondly call them zombie sub-domains.
DNS wildcards are used in a variety of ways but in this case I am focusing on the desirable redirect from a non-existent or miss-typed sub-domain to the appropriate URL (e.g. the root of the TLD).
Please continue reading my article “Why Google Dislikes Zombie Sub-Domains” at its official home on The SEM Post.