I agree running it over a longer period would be better. However, as part of the terms of the program, we are required to have our proposal approved meaning we cant start till late Jan at the earliest, then provide a report on the rewards program prior to being able to qualify for the following period. Allowing a small buffer either side, means realistically we can only operate it for a maximum of 6 weeks.
Hopefully adding in both a max and min cap it should ensure a more even distribution.