Did you notice? The Google Search Engine Results Pages Layout has changed!
In February, Google made a significant change to the placement of ads in their SERPs. Ads are now listed at both the top and bottom of the page and no longer appear on the right sidebar, leaving more room for Google’s PLAs (product listing ads) to appear on the right side. The number of ads at the top ranges between 1 and 4, depending on the search:
AdWords layout changes