Anytime I had taken my vehicles in to a shop such as Canadian tire, I would always scoff at the brake inspection, feeling it was just a money making scam. It may very well be a scam with minimal or no work being done at times in certain garages, but the need still exists. Review of brake issues such as making certain your pads have life remaining, are wearing consistently and evenly, and ensuring they move effectively in the slides are just part of the inspection. Without question the need for taking a hard look at your brakes, especially if you tow on an annual basis is invaluable. Some people aren't comfortable doing this, so find a good shop and make them show you what they are doing including movement of the pads, removal of any rust/dirt accumulations, inspection of the brakelines, quality of your brake fluid, etc. Having them looked at is good sense. Look at the recent spate of rear backing plates coming off. This is the sort of thing that could be caught.