Rand Fishkin:

The metric of “clicks / ten search queries” helps us avoid seasonality biases and look instead at the rate of queries that lead to traffic opportunity. Here, the reality is sobering.

• The high point was the first month of the graph, November 2015
• Since then, there have been two significant declines in organic clicks/query (12/2015 and 11/2016) and one significant decline in paid clicks/query (01/2016, though it’s now nearly recovered)

• The 5.41 clicks/10 queries in October, 2017 is 23% lower than the 6.97 clicks/10 queries we had back in November, 2015. That’s a lot of lost SEO opportunity

• I haven’t yet tried to tie the drops back to noted changes in the SERPs, but I suspect the growth in featured snippets, instant answers, and knowledge panels in the results are at least partially responsible

• The growth of search volume has made up for much of the lost click opportunities, but this is a tough trend chart to see as an SEO

• That said, SEO still gets ~20X more traffic than PPC, and it doesn’t cost anything close to as much, so there’s still a massive advantage to ranking organically.