This is an especially big problem for items that are differentiated on quality of materials/coatings/construction/etc. My go-to example is always lens filters:

This is an especially big problem for items that are differentiated on quality of materials/coatings/construction/etc. My go-to example is always lens filters: https://www.the-digital-picture.com/News/News-Post.aspx?News=22622 https://www.the-digital-picture.com/News/News-Post.aspx?News... It's hard to fake a believable iPhone. It's easy to fake a threaded cylinder with a round piece of glass in the middle that can fool the uninitiated.