Not saying you're wrong but the goal of advertising is not necessarily a direct, short term effect of increase in sales. It could be brand recognition, which can be activated via subliminal messaging. E.g. "I heard of you before but I don't quite remember where". I'd also say that's good. If a customer found a product from a review site, that means the customer is an informed subject who is convinced they're buying the right product. Discussion fora is more of a toss up as quality and premises of discussion can be anything really.

Re: article. The screencast (that's how that's called, right?) shows 'this visitor scrolls different' and claims that is how a mobile user scrolls. But that is also how a trackpad (laptop) user who skims through the content scrolls. Basically, its how one 'scans'. Scanning is useful to determine if content is interesting.

Anyway. Its also possible we are talking bots here. Is this possibly the effect of Ad Nauseam [1]?

[1] https://adnauseam.io

I agree with you. The primary purpose of my web sites and ad campaigns is marketing, not sales.

Nevertheless, some proceeds in the latter sphere must eventually be realised from the former, by means however diffuse...

Yeah, I hear you. I would never rely on someone telling you. If you integrate adwords with salesforce you can truly track the customer from the first click to conversion, even months later. Could be worth looking into if you want to optimize your marketing spend.

Have you ever heard that they saw you on Google at all? I feel like a lot of people fail to remember the distinction between ad results and search results.