SBN (Shared Blog Network)???

In one of the many books about link building I'm reading I found this new (to me at least) thing. This guy suggests that SBNs are better than PBNs for buying links, if one really wants to go that way.

Now, I have been dealing with PBNs for a little while now, but never heard of SBNs and can't find much info around.

Do they actually exist and are they truly different from PBNs in any way? What's your experience with them? Any you can suggest?

Thanks everyone!

Yes, they really exists, but they are much weaker than well made PBN.

This kind of SBN could be (as example) web 2.0 properties called "shared web 2.0" from some seo service providers.

Sometimes they can be better for link indexing (if you have really low PBN), but mostly in various way PBN > SBN.