Many years ago as a student I used to work in a major electrical retailer. They did and do have a reputation for being rather heavy handed in selling the extended warranty service. After all, the sales staff make much of their commission from it.
I did and do think it has its place. Some devices are tried and tested, and well maintained quite easily - fridges, freezers, dishwashers etc. For those kinds of products I don't think the extra money is really worth it in most cases (but there are exceptions).
Somewhat disappointingly some devices are considered almost consumable by people and ready for replacement in three years - mobile phones, for example, or iPods. Sad, but true. Some people might want the warranty where they don't "need" the latest gadget, but for others it would be a waste of money.
Yet other devices, such as HD plasma TVs with inbuilt bluray players and HDD are somewhat untested territory, with a lot of slightly unsteady technology entering the market where companies want to offer the best spec at the lowest price. For that kind of product, the warranty is definitely worth the money.
I was regularly taken to task for not selling enough warranty services, and was threatened with being sent for "retraining" (despite getting 100% the first time around). We were expected to sell warranties on £15 clock radios at £10 a pop, or similar ludicrous options. Some people could sell that kind of crap, but I couldn't. It had a big part in me choosing to leave and go back to selling shoes.