agreed about "best" but in terms of population it's not a "relatively small group" it's the majority.
They are all working to sell stuff - digital marketing for other companies or having ads as a core income for a site. They don't need to be devising the advertising frameworks, they just need to be thinking "how to make people click on ads".
chippy, I'll agree with you about the population (the number of people working with the LHC or Mars landers---even indirectly, as the majority of Google employees aren't working on ads---is tiny compared to say, the ad- and social-media-supported technical population of Silicon Valley), but I'm going to have to disagree with "best".
The cohort of people working on the LHC, cancer research, etc., is largely the same as the faculty of any medium sized or larger university. If you went to any research-oriented university, your professors were the ones doing that kind of research. Still impressed?
They are all working to sell stuff - digital marketing for other companies or having ads as a core income for a site. They don't need to be devising the advertising frameworks, they just need to be thinking "how to make people click on ads".