I read a study that said that most people won't hang up either out of trying to be polite or just out of curiosity.
In Canada we used to get called about a vacation club and they would always offer a free weekend at their resort if you were willing to sit through a 45 minute presentation. I went a couple of times as a lark when I was young, I went enough times that they refused me the 4th time
Hey I was young and the drinks were free and we could golf, what more could I ask for?
I don't have a fixed line anymore so I haven't heard from a telemarketer in 10 years.