leadegroot - 10:47 am on Jan 16, 2006 (gmt 0)
Do we know this to be an absolute fact or has it become an accepted truth simply because it gets repeated over and over.
I've never seen any proof for this one. In some ways it makes sense, as a network of sites (run by an ignorant fool, admittedly) might all come from the same host and therefore have the same C-class.
On the flip side - if you take a small town hosting company, then it would make sense that the majority of sites in that town would be a) hosted on the local company and b) link to some of the other sites based on businesses in that town. Would a penalty in that situation make sense? No.
But - when combined with a few other indicators of rottenness, 'same C-class' would be another piece of circumstantial evidence that a skilled bot would take into account.
I would never panic if what I thought was a good link was on the same C-class, but I would also never cross-link my own sites inappropriately.