we just have a vague sense of familiarity with the product. We instinctively buy the more familiar, as the “safer” option. It takes conscious effort to overcome this (which most people don’t have to spare).

Sounds like a perfect pitch to sell more ads. Like I said, I would hesitate to actually trust any statistical analysis of the effectiveness of advertising done by the same people wanting to sell more ads.

In a capitalist economy there’s just not a real motivation for researching advertising unless you are a marketing agency. So the vast majority of information is intrinsically biased.