[brian-armstrong]

From a monetary aspect, impressions are basically worthless. You need clicks to make any money.

[Xylakant]

I haven’t advertised on SO, but the copy text on their advertising page doesn’t sound like they’re selling slots on a CTR basis. They seem to be well aware that clicks will be rare and are upfront about that. https://www.stackoverflowbusiness.com/advertise

[fjsolwmv]

That's true for generic keyword/retargeting ads, not premium placements.