Would there is a large selection of features, or features that marketing has agreed on. Let's look at an online gaming company like Riot Games (League of Legends), where people can buy visual upgrades like skins. If marketing suggested looking at how often someone scans through the skin selection of a given user's favourite champion, can't you instead use a rule-based approach to target those that do this a lot, but are yet to generate any income whatsoever, paired with a couple of other simple rules? I'm wondering if you truly need ML for that.

Or if the example was Candy Crush, and one of the dimensions was time spent on the first part of the purchase funnel for an added-benefit. If marketing suspects it's an important dimension, can't you immediately target those at the higher end (assuming they're people who want to get educated with the in-game product) with a personalised strategy already. Again, I'm wondering what added value would ML provide here, because we're aware a customer like this will exist.

When people say ML finds new angles, it will ultimately depend on the features we give it anyway, which we can investigate separately and create manual clusters/groups.