Many of the major product listings seem to be okay—for example I've ordered a number of the Samsung Evo+ cards I link to in the blog post, and tested each one a

Many of the major product listings seem to be okay—for example I've ordered a number of the Samsung Evo+ cards I link to in the blog post, and tested each one and never found one that didn't perform as the first I bought—but I have gotten fakes here and there. Almost every time, though, it's because the Amazon official supplier/warehouse was out of stock and I accidentally ordered from one of the secondary suppliers. The problem is, unless you know what to look for in the interface, it's hard to determine if you're buying from Amazon or the manufacturer, or some 3rd party. Even then, there are many reputable 3rd parties. But there are many who are not. The worst cases in my experience are ordering 'Apple OEM' type products. I will not buy a charger or any other Apple accessory on Amazon because more than 50% of the time I've gotten a non-Apple-manufactured product.