Aren't booth babes not just a copy of car shows? I think in car shows they are doing this because of the "when you drive (buy) this car you can get all the babes in the world".

I also don't get it in sports. Why should a striptease-looking-girl give the winner the price (motorsport for example)?

I think booth babes are an expression of "I've got nothing interesting for you so I hired some babes to get your attention".