What you see on the right is a 300x250 rectangular Google AdSense Ad unit. Ideally an ad unit this size should show 3-4 different ads but maybe there isn't enough inventory [1] and therefore, all you see is 1 ad somewhere near the middle of the rectangle. When a website visitor hovers the mouse over this Google Ad block, the cursor changes from a pointer to an hand and he can click anywhere inside the rectangle to visit the advertiser's website. However, this will soon change as Google has redefined [2] the definition of a click. (more...) [3][1]
http://www.labnol.org/google-adsense-sandbox/[2]
http://www.labnol.org/forums/topic/e...nges?replies=1[3]
http://www.labnol.org/internet/blogg...783/#more-1783