If there are multiple Google AdSense ad units on a web page, it is generally assumed that the top ad unit (the one which appears first in the HTML source code) will serve the highest paying CPC ads. Well, that may be true most of the times but not always.
Curious to know the date when you can buy Windows 7? An Acer executive has confirmed the official release date of Windows 7 saying that the Z5600 touch-screen PC pre-loaded with Windows 7 will become available on October 23, 2009.
People don't just search for text. Google provides alternate search methods including image and document searches. Artist sites, often rich in images, allow an opportunity to index digital assets in search engines.