Gillette uses a different bladeset for each handle type. For example, the Mach3 cartridges don't work on the Fusion and vice versa. To entice people to switch

Gillette uses a different bladeset for each handle type. For example, the Mach3 cartridges don't work on the Fusion and vice versa. To entice people to switch, years ago Gillette mailed out free Fusion handles with a sample cartridge. The handle was free and could be used with new cartridges you bought. Now it appears that they are going to charge for the handle, which is indeed a shift