On this date Google has made one of the most dramatic changes on search results so far:
As of today there are 4 paid results at the top of Google's search results, 3 paid results at the bottom, and none on the sidebar which previously featured 7 paid ads.
This change is a part of a series of alterations made by Google. On December 4th 2015, Google has started experimenting with the appearance of SERPs by displaying 4 paid results instead of 3 at the top of their search result pages (without removing sidebar ads). Following that update the trial have become permanent. 3 days subsequent to the update Google has announced ( https://www.searchenginejournal.com/google-shut-compare-products-march-23/157163/
) that Google Compare results will discontinue its services on March 23rd for not meeting the company's expectations.
This set of changes comes to improve Google's profits and make better use of their page space.
This change is also one of the most significant yet, and several impacts can be assessed as a result of it:
1. PPC prices are going to significantly increase because now there are less spots for publishers to advertise on (all the sidebar results), and a price war for the 4 top spots is bound to happen.
2. It's difficult to know right now whether organic result clicks would increase or decrease - on one hand the amount of displayed ads have decreased significantly, on the other - the most noticeable spots, which are the first 4 results, have now become paid results. If you've noticed a negative impact on traffic to your website on this date, this result structure change would probably be the reason.