Now most of the malls or retail outlets have some kind of loyalty card to earn points on every shopping you do. If they also introduce a group loyalty card then group can earn points on any purchase made by any group member. This can be redeemed for group parties at particular food joint or some gift which can be collectively used by group members e.g. talk time among group members, birthday gift to any member etc.
For ease existing card holders can make group and get group ID, on every purchase they will get extra points under group ID as well without affecting their individual points.
How is it different from current individual loyalty program –
Outlet attracts the group rather than an individual. Imagine college friends making a group and doing shopping only from particular retail outlet.
Members become isolated from competition as inside group people are buying from one outlet only so you reduce the exposure of competitive brands within the group. It is a big impact as buyers do impulsive buying by seeing friends.
If you put more thoughts you can think of many benefits and also many ways to redeem group points.