Congratulations Iz. Have you thought about showing the popup not only on users' exit intent, but also on a sudden mouse movement after a long inactivity? During that inactivity, the user might have been researching the products in the cart, validating her purchase decision.
@mikeswcho Great point Sung, we don't have that mechanism in yet.. definitely worth looking at for sure, as it seems to be a behaviour many shoppers do!