Dugger - 3:14 am on Jun 10, 2008 (gmt 0)

The algo is also different for different keywords. That was very apparent beginning with the Florida update years ago when they not only targeted competitive commercial keywords but did so unevenly. A commercial term may have been targeted in one geographic area and not another and others were added to the "list" later. In some cases they were never added and remained unaffected by the changes.

Even today you can't necessarily apply the optimization "rules" you are using for one set of keywords and apply them successfully to another.

That makes it very difficult to define the algo with any certainty - and then when you add the frequent changes into the mix it is darned near impossible.