Crucial, (a great memory company by the way, the only one I buy memory for my Macs from,) has an ad that really is inappropriate for a Mac website. It links to their "Scan My System" tool. That doesn't work on Mac OS X. If they have a just plain "Get Memory from us" ad, it would be significantly more appropriate. If you try to run the tool in OS X, it complains of an incompatible browser, and prompts you to download a tool. That is a Windows .exe.
(And, appropriately, when I previewed my post, I got one from them saying "Guaranteed compatible memory for Macs")
(And, appropriately, when I previewed my post, I got one from them saying "Guaranteed compatible memory for Macs")