Which Side of the "Pay What You Want" Fence Do You Stand On?

OneBookShelf / RPGNow recently added a "Pay What You Want" option for the pricing of PDFs at their store.

Basically, the buyer can pay nothing or something for the product. He may pay nothing initially and come back and pay more if he likes, or not.

The secret to the success of PWYW from the seller's point of view is "volume sales". If you sell 10x more PDFs than you were moving prior to PWYP and folks are on average paying 25% of your regular price, you've still increased your sales dollars by 150%.

It isn't a physical product, so volume CAN make up for the lower average selling price.

I can see how this pricing would not work for many publishers or even most products, but as a way to sample a publisher's wares (perhaps on an older product) I can see the usefulness of the pricing scheme.

I know there are some fairly large opinions on both sides of the fence (Tim over at Gothridge Manor has a similar post up) but I'd like to see some other well thought out opinions of the perceived "pros" and cons". I'm always up for a good rant and I suspect I'll be reading a few before the night is out, but hopefully there are some decent opinion pieces too ;)