i run ten web sites. the sites are not cross linked.
site (A) which is a large site links to all ten sites on all of its pages, about 500 pages. i do this because they are all designed by my web design company, which i state. I use the same footer and header to make it easyier to update the site.
now i have designed a large site (B) with about 5000 pages which links to the other 8 sites, but not to site (A).
the other 8 sites do not link back to site (A) or (B).
So (A) links to all. (B) links to 8 sites, but not (A) 8 sites that don't link back to (A) or (B)