More appealing for advertisers, obviously. Users don't care what price was paid for a click.
And BTW, I don't feel any "excitement" about Smart Pricing. It's just a fact of life, so arguing about whether it should or shouldn't exist is a waste of breath. I am inclined to think that Smart Pricing is a good idea, though I like the idea of site-targeted contextual ads (which are coming soon) even better.