Good thread. The consensus here is correct but it's worth addressing what
@robin222 raised because it's the elephant in the room.
Some sites ARE still pulling it off with mismatched 301s and seeing traffic spikes. The reason usually comes down to one of three things.
First, the traffic spike is temporary. Google grants a crawl and indexing burst to domains with strong historical authority. Rankings jump. Owners screenshot it and call it a win. Then three to six months later the algorithm catches up and quietly suppresses the site. The spike was real. The stability wasn't.
Second, the site has enough real content and user signals to counteract the topical mismatch. If you redirect five expired domains but also publish 200 real articles and earn genuine clicks and engagement, Google weighs all of that together. The redirects help but they're not doing it alone.
Third, some niches are just less competitive. A mismatched 301 that would get buried in finance or iGaming might hold in a low competition niche where Google has fewer strong alternatives to serve.
On the PBN side of this
What
@jennykumar described is exactly the right mindset. Warm the domain first. Build topical relevance before you redirect. Treat it like a real asset, not a shortcut. The people getting burned are skipping the warming phase entirely and expecting a cold redirect to transfer full authority overnight.
The method isn't dead. The shortcut version of it is.