Let's say I have a page optimized for "widget training" because it pays 2/click. But I've started an adwords campaign with the word "widget" because it's only .2/click. Will Google lower your quality score due to relevancy because the page contains the keyword "widget training" instead of just "widget"? Or does it not know the difference? How does Google distinguish between a root keyword like "widget" and derivations like "widget X"? I was wondering this not only for adwords, but for adsense as well. If you're trying to optimize a page for adsense for "widget training," how does Google know to show ads for "widget training" instead of just "widget"?