Great info here! Is it worth it? Hard to say without knowing what your goals/niche are. A small PBN of 10-20 web properties can make movements in a lot of niche's, however to make a dent in some of the more competitive ones, you'll need to scale way beyond that. Obviously the more you scale, the more costly this strategy becomes. But I find it risky, you should come up with an ultimate guide to PBN Safety post.