I know about the niche relevance, but how many sites can I 301 to my money site?I think it all depends. For me, I redirect on occasion, but it's very niche-to-niche so it looks realistic. For instance, I won't 301 a site that sells men's shavers to a site that reviews dog treats.
Do the 301 sites need to have content on them, or is it ok if it has nothing? Also, how many should I 301 to my site?