I am not sure about suggestion 1 as that is just a fares cut - BUT I think your second suggestion has some merit.
For quite a few years the Isle of Man Steam Packet company used to do this with their Irish Sea Sailings and it even extended to other routes when the company was owned by Sea Containers Ltd.
Basically you saved your tickets for five sailings added up the total and then noted 20% of the value. Presented the savings wallet at a terminal and they would give you 20% of the value of those five sailings against the cost of another ticket. - Was a very popular scheme but ended when Sea Co went bust and they were taken over by venture capitalists. (It was Nationalised by the Isle of Man Government just over two years ago).
It kept people loyal to the ship and kept them away from the airlines.
I imagine with online bookings such a scheme could be brought in by TOCs to maintain customer loyalty as journeys could be recorded on the customer's account.
Might avoid them going to competing TOCs, defecting to National Express or going by car!