Google has confirmed that it will change the way adverts are displayed by moving to a three or four advert band at the top of the search results page in its search results following several years of display tweaks. This could be bad news for small businesses, from both PPC and SEO perspectives.
Read the full article by Rebecca Appleton on Wordtracker: http://www.wordtracker.com/blog/google-confirms-a-four-ad-format-ending-sidebar-placements