Private blog network (PBN)

The classic construction uses expired domains that still carry links from their former lives, dressed with thin content to look like independent publications. The whole design is to manufacture the appearance of unrelated sites endorsing a target, which is precisely the pattern search engines invest in detecting.

PBN links are attractive because they are fast, cheap, and completely under the buyer's control — and they carry the corresponding risk. Because a network shares owners, hosting, templates, or linking patterns, discovery tends to be all-or-nothing: when one site in a network is identified, the rest are trivially found, and everything they point at is reassessed at once.

The practical relevance for buyers is supplier diligence. Link packages sold at a fixed price per link with a promised metric and a fast turnaround are frequently PBN placements described in other words, and the site owner buying them carries the consequence, not the vendor.