One day recently I was doing some Google searches for patents regarding link networks when I came upon the Information retrieval based on historical data patent, published in late 2008.
..A typical, “legitimate” document attracts back links slowly. A large spike in the quantity of back links may signal a topical phenomenon (e.g., the CDC web site may develop many links quickly after an outbreak, such as SARS), or signal attempts to spam a search engine (to obtain a higher ranking and, thus, better placement in search results) by exchanging links, purchasing links, or gaining links from documents without editorial discretion on making links.
…if the content of a document changes such that it differs significantly from the anchor text associated with its back links, then the domain associated with the document may have changed significantly (completely) from a previous incarnation. This may occur when a domain expires and a different party purchases the domain… All links and/or anchor text prior to that date may then be ignored or discounted.
This patent seems to suggest that buying an existing domain and redirecting it to a different domain in an unrelated industry will cause the search engines to ignore the links to the domain that has been redirected.
But what about this example that Rand found a while back? He tweeted:
A Special Case
This is a special case. Rockwellcollins.com is ranking for the term “SEOs” because they bought the domain name “seos.com”, but instead of redirecting the site, which would theoretically negate the links pointing to seos.com, they are mirroring their site to seos.com. Google now seems to be inferring a canonical tag.
Given, rockwellcollins.com does not care about ranking for the term “SEOs”, but don’t you think that this inferred canonical means that the domain authority of rockwellcollins.com is being helped out because of the links to SEOs.com?
This should not happen, theoretically, because of the patent listed above. But it is.
Bad Google. Very bad indeed.