from Mathias Brandt, July 18th, 2014

With 22 percent more revenue and a $3.4 billion profit in the second quarter, Google is flourishing. All that money is stemming from the search engine’s thriving advertising sector and the 25% increase in the paid click rate between April and June bears testament to that. Remarkably, however, the price of Google ads are falling. In fact, the average cost per click (CPC) has been declining for over two years, falling 6 percent in the second quarter of 2014. The last positive change occurred in the third quarter of 2011 when it rose 5 percent. All quarterly figures can be found at Google.

This is an excellent scrolling graphic that gives a visual storyboard of how Google uses keyword phrases that are inputted into their search box to provide the best possible results.  
Very fascinating just how much data is being crunched stored and indexed...

How Search Works