I bought an extended warranty on a new TT about 12 years ago. It was for 4 years. In that time I tried to use it 6 (if memory serves) times. Only once did they part with actual money and that took months - fortunately I hadn't planned on using it during that period. They didn't cover call outs, the unit had to go to an 'approved' repairer - a list of which was 'not available' and they would not necessarily cover the complete cost. Treat it like medical insurance but with less chance of personal suffering.
I wouldn't go so far as to say they are a scam, quite - but they don't exist to pay money out.
In our situation (ex-rental units) the appliances and everything else are as simple as possible to enhance the lifespan. There's very little to go wrong {edit to add - as long as you keep up with basic maintenance}. My personal response to the offer of the extended warranty was to glance at the fine print, chuckle, and politely refuse.
