Savings from Dimmer Switches

Just installed a dimmer switch, which had an energy savings chart on the side of the box. No surprise on the energy savings from dimming, but what I found interesting were the claims about extended bulb life (presumably for incandescents) --

• Dimming lights 10% | reduces energy bill 10% | extends bulb life to 2X
• Dimming lights 25% | reduces energy bill 20% | extends bulb life to 4X
• Dimming lights 50% | reduces energy bill 40% | extends bulb life to 20X
• Dimming lights 75% | reduces energy bill 60% | extends bulb life to >20X

(From a Leviton Dimmer Switch)