I just saw someone who conjectured that a new site had been 'de-indexed' by Google for having interlinking sites. What's that?
basically, as i understand it, "interlinking sites" in the context of de-indexing and being penalized by google, is when you have, say, 100 websites on the same server, similar or duplicate content, all pointing to each other, so that each site has 99 backlinks (one from each of the other 100 sites on the server) in an effort to trick google into thinking that you have 100 sites with 99 backlinks each. for example, site a links to site b, c, d, e, and f site b links to site a, c, d, e, and f site c links to site a, b, d, e, and f etc... and all 5 sites are on the same C block IP address, google will see this as a bogus attempt to create a pseudo-backlinking structure, and this attempting to thwart google's algorithm.