One thing I have wondered for a little while is how all these learning algorithms will handle change over time. A lot of my advertising is for things I may have liked perhaps 5 years ago, but no longer have anything to do with. It's also a bunch of super wrong things, like parenting, even though it also thinks I'm a single male who likes holidays, and skiing, even though it doesn't snow where I live and I've never even entertained the idea.

It's clearly confused, and so my wonder is how do they correct that over time? How do you un-scramble a scrambled machine learned profile? Can you even detect that it's gone awry?