@diberry - Sorry if I digress from the Zombie topic for a moment, just thought I'd share an observation, since you mentioned it...the "how to" phrase seems to have some new value placed on it. I lost all my positions that included that particular phrase. Doing a site search, it does not appear to be overly used. Only bigger platform sites seem to have been awarded that phrase, even though the are ridiculously stuffed with the term. What's funny (sickeningly so) is that they removed my organic results completely and optimized my Adwords ads to show up on those pages instead.
They seem to be getting wise to what we sell and know which organic results to pull and replace with cpc ads. Problem is, the adwords ads are not producing either. The end result basically appears as throttling.