None. They just let Marketing explain that "Dead Bulb" is a feature.
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1,000,001: One to change the bulb and 1,000,000 to rebuild civilization to the point where they need light bulbs again.
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In the neigh-borhood.
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Nothing, peanuts don't talk.
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Three. One to climb the ladder while the second kicks the ladder out from under her. And the third to say, "I knew that was too high for you dear."
or