A Private Blog Network is a privately owned network of servers that has obtained high domain authority via some means (generally via what where called Black Hat SEO techniques) and from which links to other websites were sold.
Private Blog Networks were rendered ineffective in 2013 or 2014 via one of the Google algorithm updates, yet you still occasionally find people trying to sell links from their Private Blog Networks.
Are private blog network good for small businesses?
As much as there are number of pros of private blog network like control, instant authority, and building relationship,
The following are 3 reasons why you should not use a Private Blog network
As Google updates their algorithm (which occurs almost every day) they undo ways people game the system. One such trick to game the system (that used to work) was the use of Private Blog Networks. However Google has rendered them ineffective.
Uisng the services of a private blog network places your sites ranking at risk.
Your sites can have their ranking reduced and even be de-indexed for having Unnatural Inbound Links.
Developing and maintain a network is very costly. For that reason the cost of links from private blog networks can be high.
If someone approaches you with an offer to sell you high authority links to your website, be VERY skeptical. If you have any doubt as to the legitimacy of what they’re selling, do not buy.