It’s widely known, and proven, that brushing our teeth for a minimum of two minutes is required for good oral health and hygiene.
And although electric toothbrushes are widely regarded by dentists as being superior to manual toothbrushes, I think they stand atop the podium because of one simple thing: the two-minute timer. It removes the need for measurement and thinking. It turns an action critical for our health into something automatic.
Although the invention can’t be attributed to a specific person, I’m grateful that someone, or some group of people, back in the 90s pushed for this to become a standard across all electric toothbrushes.
The benefit to cost ratio is difficult to calculate, but I bet it’s insane.