If you are a habitual coffee drinker, you have surely got memories of days when, after not getting enough sleep, drank a few extra cups only to end up only crankier than before. Offices with unlimited free coffee facilitate this trap pretty well.
So now you decide to cut back on coffee and find that keeping track of the number of cups consumed is a chore, especially if you are busy because of meetings, deep work, or anything more intellectually stimulating than finding the thing that you use for tallying.
Having a cup with a built-in dishwasher-proof clicker to keep track of cups drank would be a pretty handy solution to that. And nothing stops you from using it to count other things once you fixed your habit.