Forum Moderators: Robert Charlton & goodroi
1. Adwords = down in SERPs
2. Adwords = up in SERPs
3. No cause and effect relationship
The official word from Google is that there is no relationship between AdWords and organic search results. And although in isolated cases there may seem to be a relationship, it's just a coincidence in timing - neither theory #1 or theory #2 holds up over large amounts of data.
Google's official stance on this rings true. Plus, it would be business suicide long-term for them to establish any connection.
There is an easy to make logical pitfall known as "post hoc ergo propter hoc" which translates to "after this, therefore because of this". Even when you see a pattern over huge amounts of data, there's still a difference between merely correlated factors and establishing a true cause and effect relationship.
However, if you have a theory about cause and effect in any given situation, then all it takes is one counter-example (where the other variables are controlled) to disprove that theory. When you manage large AdWords campaigns and also monitor natural listings for the same words, it quickly becomes clear that there is no cause and effect relation between AdWords and the organic SERPs.
Absolutely none.