[riku_iki]

> number of people never click, but do remember and come back later

For major brands they may remember. Otherwise I think it is reasonable to assume that clicking on ad is most established way for user to check product. Once user navigated to website, he can be reliably tracked by site owner.

[mr_crankypants]

Possibly. But, at the same time, "it is reasonable to assume" is the epitaph carved into the gravestone under which economics's credibility got buried alive.

I'd feel better assuming that question's answer is simply unknown until a few different people have performed a few different field experiments.

For my part, for example, I pretty much never click on ads, because they typically get shown to me at a time when I'm already busy doing something else. But, if I later perceive a need to buy a product of that kind, there's a decent chance I'll remember the name, and therefore be more likely to Google them or take a closer look when I see them mentioned on Wirecutter. I have no idea how typical I am on that front, but, tangentially, I do at least suspect that, if clicks were really the end-all-be-all of hawking product, then there wouldn't be quite so many billboards by the side of the highway.

[riku_iki]

> I'd feel better assuming that question's answer is simply unknown until a few different people have performed a few different field experiments.

there is whole industry of such people, and they vote by investing dollars into specific type of advertisement, which is reflected in Facebook and Google revenues growth.

> likely to Google

This is another channel of how dots can be connected.