Opinion Marketing is coming to terms with a new world order. Until last year, that looked like a gradual but fairly smooth transition. In 2019, two of its industries took a beating.

One was advertising. The other was SEO. While the advertising industry was being attacked, by and large, by aggressors outside its control – an increasingly fragmented media landscape, its own increasing fragmentation, budget and time pressures and a shift in the balance of power between client and...