Alice, Bob, Carol, and David share an elaborate dinner together at a trendy restaurant and Alice pays the bill in full. Bob, Carol, and David each should then be able to transfer one-fourth of the total amount in digital cash to Alice. The digital cash should be transferable to other users. Essentially, peer-to-peer payments are possible without either party required to attain registered merchant status as with today's card-based systems.
This is a very important element if digital cash is to replace ordinary cash. Think of situations where you hand money personally to someone else, e.g. as a gift, as charity, or as a tip. It is important to waiters to have some means to supplement low pay.
There are also other person-to-person payments for which only cash is regarded appropriate, like payments to children, friends, colleagues or neighbors.