I was looking at Priceline.com's business model and it got me to thinking... what would be the feasibility of a provider's version of this?

All too often we see posts from providers saying they have plenty of available appointments.  Like a hotel room, if these appointments go unfilled, they lose those potential earnings.  What if something was set up so that clients could "bid" on these available appointments, and get them at a lower rate than pre-booked appointments?  Like priceline, however, the client could only specify a time-block for the appt (as opposed to a specific time) in exchange for the lower rate, or the identity of the provider wouldn't be revealed until the meeting, etc...  The client would bid based on reviews/ratings, like hotels are rated by stars.  Ladies, I'm not comparing you to hotels so please don't take offense to this; I'm just referring to a business model.

I suppose the most important question is whether providers be willing to fill their open appointments at a lower rate.  I've spoken to a few ladies with differing opinions.  Your thoughts?