So I was thinking on my ride home- why did Gillette develop new razors during the DE period? If Gillette really made little money on the razors but made real money on the blades, why continue to do R&D on new DE razors? The old three piece razors would work well enough to sell blades. If someone else developed something better, as long as it still took DE blades, why would Gillette care? I understand the new razor treadmill in the cartridge era, but not during the DE.