Peddling useless even ludicrous 'products' makes money because people are both morons and have too much money. "There's a sucker born every minute" P. T. Barnum used to say.
The trick is to make a profit at $19.95, wait, make that not one but two useless finger-removing Chinese made electric toe-clippers for $19.95 and throw in a years supply of glass-shard covered emery boards.
Witness this cuddly cacophony of counterproductive contrivances. First, the self stirring coffee mug, above. In the hands of an unskilled caffiene-fiend this java-juggler will surely be the envy of any gathering brood of pathetically lazy mocha freaks.
Not satisfied yet? You can also get a little refrigerator robot that both stores and pours soft-drinks alleviated the need to pop the top yourself. Or how about a wire-device that puts your socks on for you? How comatose does one need to be to buy a sock-put-er-on-er?
Ultimately Rube Goldberg had it right. Mankind loves gimmicks and gadgets. Even if the goodie is a solution to a non problem.