adsAreAScourge

How does this work (economically)? Based on this subthread: https://news.ycombinator.com/item?id=11804689 it seems that the mechanism is:

HTTPS site can't load resources over HTTP (due to security) -> only those advertisers who support HTTPS can place bids for HTTPS-only sites (and not all do) -> the smaller number of bids results in lower ad revenue

However, as also noted there, the advertisers who do support HTTPS should preferentially bid for impressions on HTTPS-only sites, since the price per view (or per click etc), is lower. Importantly, they should continue doing this (raising the price of adverts on HTTPS-only pages, due to the increased demand), until the price per click etc. is the same for HTTPS-only and "normal" sites. Why does this not happen?

i) The simple model above is overly simplistic, and I don't actually understand the situation,

ii) The marginal costs of serving HTTPS ads and HTTP ads are not the same (though why would that be — the server overhead for HTTPS is marginal) or the the revenue from HTTPS vs. HTTP ads is lower (but again, why?),

iii) The time-frame is too short(?),

iv) Advertisers are turning down free money (highly unlikely).