1. The Gillette Mach3 was a breakthrough product that introduced a triple-blade razor system, providing a close, comfortable shave with less irritation. 2. It took Gillette 7 years and $750 million to develop the Mach3 through extensive research and prototype testing to design a razor that could shave closely and safely in fewer strokes. 3. The Mach3 became the world's best-selling razor due to its innovative triple-blade design, lubricating strip, and angled blade configuration that allowed for a quick, comfortable shave without needing additional shaving cream or a second pass.