I worked for an appliance and electronics parts distributor in the mid 80's. Back then, we looked up OEM parts on microfiche, paper service manuals, etc. We would get letters and phone calls from consumers looking for all kinds of parts.
Fast forward to 2015, I want parts for my Whirlpool Microwave, I google what I am looking for and I find AppliancePartsPros.com. I put in my model number and a parts list, with pictures of the service manual showing where the part fits, assured me that I was getting the correct part.
Prices were right there, easy to use web site, payment via credit card and super fast shipping.
Parts arrived within a couple of days. Simple installation because of what they are and works great. Easy, peasy.