There's quite a few promising less cancellations, less churn but I haven't seen less chargebacks yet. Usually they tell you to give customers offers during cancellation, e.g. a discount, months free, anything so they don't click the final "cancel now" button.

They're mostly just typical UI/UX or business consultancies trying to fit their way in the niche by offering vague advice and "data-driven analytics" services. I don't have a great deal of confidence that the average business analyst couldn't do better, but some companies don't trust their staff and need to pay someone to tell them otherwise.