This is a common grey hat SEO strategy that borderlines between black and white SEO.
It refers to buying a domain that the owner has let expire but still has a lot of authority because of the number and quality of backlinks still pointing to the site.
A gray hat SEO method with expired domains can be applied in two ways:
- Using a 301 redirect to redirect all of the link power to your current domain to improve its authority.
- Going to a site like [Wayback Machine ,finding archives of the old content, and republishing it on the site to resurrect it back to how it was before the domain expired. This can give you an instantly successful website with targeted traffic.
Buying links and trading links are the second most popular grey hat SEO techniques webmasters use to increase authority and rankings for their websites.
However, link schemes like this are technically black hat SEO tactics because they violate [Google’s Webmaster guidelines.
Building a micro-site or blog is a gray hat SEO technique that can improve your search engine rankings without getting penalized.
Spinning content is another common grey hat SEO method that can work for getting ranked in Google
Duplicate content is another gray SEO tactic that’s being used in the world of search engine optimization these days.