Question: Does Facebook activity affect SEO?
Broad Answer: No.
However it’s not that simple….
Definition and SFO:
In this post I am directly referring to how Facebook optimisation affects the Google SERPS. If I were not, and instead referring to how optimising Facebook for Search on Bing and Facebook Graph Search, the answer would be a resounding yes.
And here’s some detail on the topic of Search Facebook Optimisation (SFO) from my own site
Also if we are talking of Facebook’s impact on Social SEO seeding then again Facebook definitely has a part to play.
Top Level Conclusions
Note: This section has pretty much been stolen from Eric Enge; someone I had the honour of discussing SEO & PPC with a few months ago and whom definitely knows his Search onions
Google does not use the raw aggregated link data at its disposal to aid its ranking algorithm.
Facebook shared links do not appear to be used to aid indexation. Neither is Google indexing all shares of superstars hence it cannot be taking this area too seriously.
QDF (Query Deserves Freshness) does not appear to be utilised for Facebook posts when pertaining to indexing fresher content (other than with images).
Interestingly Google can see who your friends are by crawling the mobile version of Facebook but chooses not to/ does not utilise the data (but then why would they when they have Google+ ?!).
…note: For more information on how Google+ affects SEO see my 4 key tactics on how to utilise Google+ for SEO post