There's a lot of good feedback to chew through, but I'll refrain from diving in too deep, and just mention that, as important as the HVA/DSI methodology is, there's been a comparatively lower amount of research done in "negative HVAs". In theory, one can do the same type of analysis to compare "twins" and pick out the NEGATIVE value of having repeat payment problems or repeat unsuccessful customer service interactions. Optimizing for growing the positive HVAs, is fundamentally different from optimizing to reduce the negative ones, but Amazon has the tools to get there or to do both, if it wants/needs to.

And yes, 12 months is arbitrary and doesn't capture everything, and longer windows of analysis are possible, but waiting even longer just throws the signal-to-noise ratio too far in the direction of noise.

FWIW, I no longer at Amazon, but I've yet to see a company of significant scale apply this level of econometrics so rigorously in day to day business decisions, or that they would evaluate 12 months as a baseline (most companies and most A/B tests are much shorter, obviously). I'm sorry you've had bad experiences, and anyways I think it's overall good for society to cultivate strong alternatives to Amazon, but as invisible as it may be to you as a consumer, your data and your lost value as a customer are definitely accounted for within these methodologies, even if no visible changes are happening or they're not winning you back.