What are the reasons for unnatural link building and therefore against the guidelines?
Links with a very hard anchor text (e.g. “vacation”)
Links from the footer (side-wide and in the non-visible area)
Backlinks that have been created unnaturally (e.g. commercial)
Unnaturally fast backlink development (period)
Links from link lists, article directories and web catalogs
Links from thematically irrelevant websites (unnaturalness)
What are Google's policies?
When the first Penguin update was released, Google already wuhan cell phone number list stated that high-quality content should be given priority over spammy sites. Adhere to the Webmaster Guidelines. Google has already established the ground rules :
Create pages primarily for users, not for search engines.
Avoid tricks designed to boost search engine rankings. A good indicator is whether you'd be comfortable explaining your approach to a competing website owner or a Google employee. Another helpful test is to ask yourself the following questions:
Is this beneficial for my users?
Would I do that even if there were no search engines?”
Consider what makes your website unique, valuable, or engaging. Design your website to stand out from others in your space.