The other night, I caught a couple of commercials for Craftsman
products. And I wondered what sort of market research they were doing.

For example, they show how their circular saw with a laser guide enables
a user to make absolutely straight cuts. I thought, "That's nice, but I
can clamp a straightedge to the board and use that as a reliable guide."

Then they showed a lawn mower with a switch for the blades, enabling the
user to stop the blades when the thing runs over a sidewalk. Not a bad
safety feature... but when I cut my lawn years ago, I'd simply tilt the
thing back so the blade lifted away from the concrete.