Brian no one can say for sure, only Google. It is clear Google does not like paid placements. Also it is really hard to say if these changes that were off site did anything to effect rankings.

It could be Google simply doesnt value your backlinks as it once did, thus lower your positions. Google devaluing other websites and its OBL's happens all of the time. it leaves the websites that those website are linking grasping at straws as to what happened.

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