Google has announced they will soon be removing the right hand side adverts showing on the search page. They will be limiting the number of adverts to just those at the top and bottom of the search results. Even though they are removing the right side ads, they will be adding an additional advert at the top of the page.
The changes Google is making will apply globally and will help the desktop search match the mobile search. Google plans to continue to test this new strategy and make changes, as necessary.