How would you feel about a fun feature/initiative to encourage the use of the split bill feature whereby all users that split a bill are entered into a lottery each week and Monzo reimburses the lucky winners up to £100 for the bill that they split. Each time you split a bill you would earn one virtual lottery ticket, and if you win that week you’d get a push notification and the money would pop up in your account - you could then pay back your friend their half of course.
The initiative could be summarised in the tag line: “Split the bill and we might just pick it up for you”.
It’s a way Monzo could encourage the use of the feature and thank the most active users though a fun giveaway rather than ads or notifications.
Additionally, all users that split a bill with a non-user could be rewarded with a golden ticket, so they can invite their friend then and there.