alt Hacker NewsShort answer, any ad that leads to a non regretted purchase the viewer wouldn't have otherwise made.
The instantiation I'm working on is to track the viewer's long term goals and the habits they're trying to form, then only show ads relevant to those. Ads today are shitty because people with products that add no value to anyone's life can somewhat overcome that disadvantage by bidding more on ad space, so that's what we see. But there are plenty of products that would actually add net value which it doesn't occur to us to look for, and insofar as ads exist, they should help us find them.
This project (my working title is eudaimonia) aims to let the user essentially aikido the attention economy arms race by saying "here's what I think would add value in my life, you may pitch your product iff it's actually relevant to that".
To me, that doesn't seem hugely different than current advertising. "non-regret" is a low bar. It's still, of course, treating increased purchasing/consumption as a good thing. And it still has the same characteristic of pushing users toward inferior, more expensive items because it makes someone more money that way. As in, if you have items A and B, and a user gains 1 value from A at a cost of 100, but would gain 10 value from B at a cost of 50, a "good ad" could make the user purchase A instead of B, which is a relative negative impact on their life. Additionally, it doesn't address the harms caused by "track[ing] the viewer"