That would indeed be awesome. Things I might add on to this are:
maybe 10 -20% off instead since 50% is quite a lot. Also that the line getting the discount is the one with the lowest rate plan. This would prevent things such as "ex. Having a $40 plan and getting a big discount on a plan that is $60 on line 2." This is just stuff I thought I'd add to make the idea seem more reasonable to koodo.
Great idea though Sharan!