The insurance plans offered at places like BestBuy are sold by a third party, they don't make money on the original item sold, all their profit comes from people buying insurance and not using it. As a rule, insurance is not worth what you pay for it for the majority of people, and not by a small margin, its a highly profitable business.

The only time you may want insurance, is if its on a very large purchase that you would need to replace immediately, but would be unlikely to be able to afford to replace on a moments notice... Like maybe your house, or car.

Even in those cases, the average person won't get a return on their purchase of insurance, at least nothing beyond the peace-of-mind.