This may be one component of the success of Google advertising platform versus other online advertising options. If you want to make a significant spend on advertising with a large publisher (or set of publishers) you pretty much have to pick up the phone.
I know when I'm evaluating a service or software package, I'm much more inclined to go w/ an option that publishes pricing up front and allows me to "self-serve" my purchase, versus emailing or calling a sales-person to essentially negotiate the price.
I know when I'm evaluating a service or software package, I'm much more inclined to go w/ an option that publishes pricing up front and allows me to "self-serve" my purchase, versus emailing or calling a sales-person to essentially negotiate the price.