Google changed its search engine results page (SERP) display in February, opting to remove the advert strip that used to appear on the right hand side of the SERP in favour of top-down adverts only. The change immediately resulted in less ad impressions per result page, but the concern was that with less positions, biddings would rise and click throughs would fall. It now appears those concerns were unfounded.
At Bookassist the Digital Marketing team have been monitoring this on behalf of Bookassist client hotels and have seen no appreciable change in advertising cost (Cost Per Click). In fact, Search Engine Land reports the same findings, and also reports that click-through rates have actually improved for the same traffic.
For more details on this, see Search Engine Land http://searchengineland.com/googles-right-side-adpocalypse-really-happened-data-245011