hutcheson - 6:17 am on Aug 18, 2006 (gmt 0)

Google gives lists of artificial page rank promotion schemes that have been actively targeted (cloaking, hidden text, mutual-admiration-society link exchanges, etc.): but they've always said "any kind of artificial page rank inflation scheme" is risky.

If there are SEO techniques that don't involve some form of artificiality, they aren't common enough to be concerned about. So, at any time, Google could add a new item that can be DETECTED (and therefore treated as a negative factor in the genuine-page-rank algorithm). Very likely, among all the SEO tricks you did, at least one of them is now being negative weighted.

The question isn't whether a given trick is "dodgy" enough. The question is always whether the presence of particular TRACKS (perhaps typical of a given TRICK) indicates poorer quality sites on Google's test searches, in the opinion of Google's QA reviewers.

So a particular coding practice could suddenly become a detriment to your site, because low-quality-page-generators all got together to start using it (or, for that matter, because all the low-quality-page-generators in this month's QA searches happen to use it.)

It's a natural effect of random human efforts to subvert a fixed member of a class of algorithms, and necessarily incomplete analysis of the choice of which member of the class is (on the average) least successfully subverted--today.