Google

According to an SEO blog, these are the most important tools to use from Google.

The importance of Social Influence on overall SEO, and Google's approach.

The growth of Google for Advertisers and the various Countries reached by the programs.  

A summary and breakdown of Google's main strategies.  

These reports will show the return on investment (ROI) on the PPC campaign and show how the campaigns help to drive traffic to the site or custom landing page.

Update on Googles undercutting apple with  one-pass

This article talks about how and why google is so successful and keeps expanding

Talks about threats that each Apple and Google have on each other.