Costs per Click go down the higher the Clickthrough Rate is, which makes sense: Google prefers your ad, since it makes more money off more clicks. Page Quality

Costs per Click go down the higher the Clickthrough Rate is, which makes sense: Google prefers your ad, since it makes more money off more clicks. Page Quality also supposedly influences CPCs. That currently depends mostly on the pages loading speed and whether the page actually relates to the keyword you're buying, so basically the same way they rank organic search as well. So yeah this Search Algorithm change might have an impact on ads as well.