Based on no scientific evidence of my own, I would imagine they just went away because the trend of those kinds of banner ads simply kind of vanished. I haven't seen very many "Lose belly fat with this one secret tip only single moms know" ads in a while (I think they were all pitching Acai or something). There are definite trends of ad types across the various ad networks, but like any other market looking to hawk the-next-big-thing, I would think they dried up because business was elsewhere.
evergreen ads still convert, maybe you have adblock turned on?
Maybe they were replaced with "One cool trick that will save you thousands...", "President Obama said..." , and "[Insert big industry] hates this!" ads. I see those all the time.
Yes. This. If you turn off adblock, you see ads like "How does mom in [Your geolocated city] make $55/hr staying at home? Find out how!" all the time.
December is usually dominated by brand advertisers and holiday shopping ads which pay a higher CPM than direct response advertisers (like "shoot 5 ducks" and "you are the millionth visitor")will pay. You'll see these ads again come January, when CPM's drop to their normal rates.
I Am Not In Web Marketting, but based purely on my observations, they were replaced with Commission Junction, Google, & Amazon driven ad networks which mercilessly target you with ads for consumer products you've recently looked into buying.
They are still with us, unfortunately. Maybe you don't see them because you live in a country for which there are enough proper ads. I ... I see them all the time, though admittedly less than I used to.
Yep. I moved to the Czech republic 8 years ago, and those ads are still live and kicking out here.
I've got most of them blocked at this point (Ad/FlashBlock), if I actually do see them I put more mental energy into the actual blocking than consuming the content.