Without publishing an announcement Google has removed right sidebar ads from desktop browser search pages, now showing up to 4 paid ads at the top of searches before organic search results and up to 3 at the bottom of SERPs (search engine results pages). I'd like to think Google's update was inspired by the latest web design trends of 2016 which are shifting towards minimalism, simplicity, fewer simultaneous choices, and other feng-shui-like principles.
The change will significantly affect click-through rates and likely cost per click paid by advertisers for existing Google Adwords campaigns, especially for high traffic commercial keywords. The SEM Post reports that Adwords staff have confirmed that this change will be worldwide and permanent.
Previously high traffic searches would have 3 text ads at the top which will now change to 4 for highly commercial searches. The term 'commercial searches' will likely be any searches that yield high advertising revenue such as high CPC (Cost Per Click) and high volume search results with commercial intent.
Mobile search browsers won't see any changes for the time being and still display 3 text ads at the top of the page with up to 3 ads at the bottom of each search results page.
Google has been making lots of subtle changes to their search results page for a long time now, often performing many different experiments simultaneously across millions of users to optimize the experience of users based on changes in behavior patterns.
The removal of right sidebar ads, which are often ignored by savvy Google searchers, may be part of a longer-term strategy of Google attempting to make the right sidebar more useful and eventually more profitable through other forms of enhanced and more trustworthy content delivery. So just when you were about to sit back and enjoy the new whitespace of Google's new search page web design, you may need to start getting used seeing new more useful content there.
Examples of these shifts can be seen when searching for popular music groups which produce a wikipedia type fact chart where the right sidebar ads used to be. The change may also be partly associated with revenue models Google has calculated related to trends in revenue from ads in the sidebar compared to ads placed above organic content.
Either way, I'd like to say a big AMEN to whoever at Google had the smart idea to remove a little more clutter from our lives. They've done a great job of keeping their homepage clutter-free for so many year. Perhaps Google is now making this change in response to new trends in web design that are moving websites towards more simple, light-weight, and less cluttered designs for people searching for valuable information online.