Earlier this year, I ordered Gillette Mach 3 Turbo razor cartridges from a seller on eBay.  My Husband used one and the blade just about PULLED the hair out of his face.  I called Gillette to report the problem.  They said that this has been a huge issue for them, and that there are a lot of counterfeit razors being sold on the internet.  The way to tell if the blades you have purchased are fake, look at the clear plastic case that holds the blades.  If there are no numbers printed on it, then the blades are fake.  My Husband pulled out a box of blades we bought at Walmart to compare the packaging.  On the real box, the printing and design are raised.  On the fake box, the printing is pretty much flat.  These counterfeiters do a really good job.  Just beware of who you're buying from.  Really READ their feedback and look at how long they've been a member.