Very interesting post.
But I wonder who pays for what I call "grey area price matching"
My example of this would be things like no frills (for example) have a sale on condensed soup (cream of tomato, mushroom, chicken noodle) and in their description they have the wording of assorted variety. Now I take that flyer into rcss (for example) and use it to buy the more expensive cream soups and the cashier does the deal.
I would think that after a while if all the mfgs would either started to refuse giving them the money back or coming up with new guidelines around what the mfgs will cover or not then the stores might either stop price matching or making it really hard to do it.
I use the price matching for things like getting the good price but if I buy it at no frills I will also get points, but I know a lot of people that do not have access to a car pm as a way to bring down their overall grocery bill and do it in a one shop.
I know this post is a bit off of topic but in the area I live, most of the stores have or are changing their price matching rules and I'm sure it is because of abuse.
If it does go away I'm sure going to miss things like regular price - price match + instore points + points offers - coupon = really good deals :)