I met a client yesterday and he asked me a question I.e. weather hamburger menu should be placed on the right side or left side of the page. My answer was to place it on the right side because logically right side is the easy access to any user using mouse or track pad but his was counter was obvious that, why are everyone following left navigation (Amazon.com, fb.com). I was answer less for a minute. I know all the theory says left or maybe it's been a practice ever since hamburger menu was introduced. I'm finding hard to accept left side placement though I've used left side in many of the projects.

Please help me understanding this.