Well, yeah... especially the part where you win the money would be more fun if you do it yourself, rather than watching someone else win. :)
But if the questions are a bit interesting its already a good start. Something better than "Which Rapper published the album XYZ in 2004?"
And yes, there is this factor of "will they make it?", especially also in Cash Cab. I guess we all have a certain perception when we see people the first time, and we make assumptions about their personality, intelligence ect. I guess thats also part of it.