PBN's (Private Blog Networks) work great. But the links you will buy publicly are Public Blog Networks. In the past, you would be penalized by Google if you were caught using PBN's, but that gave birth to negative SEO. You no longer had to use PBN's, you just needed to buy some PBN links for your competition then report them to Google and they would be deindexed. Google caught on to this and today they will just deindex the PBN and you will lose the link.
Private blog networks, are private and not offered to the general public. Third-party crawlers are blocked and the only one that knows they exist are the owners and search engines. These links boost your rankings and will last for a very long time.
But the links you are buying here are public. They do work to get you ranked but It is only a matter of time before they get indexed and when they do your ranking will go back down. If you are going to use PBNs pay for links on a monthly subscription, or at least ones that have crawlers blocked get the longest boost.
