Penny auctions are not really the mainstream and they still cater to a very niche audience. That doesn't mean they cannot go mainstream. I think Quibids has the best chance, owing to its Buy It Now feature, though there are many issues that Quibids still needs to iron out.
Penny auction commercials are the way in which penny auctions project themselves to those who do not know about this auction model. However, they need to do a much better job. Take this commercial by MadBid for example:
I mean seriously?
Penny auctions need to present the whole picture. All they seem to be interested in, however, is how to convince people of 90% discounts. This is partial truth - no one advertises that you can lose money too! I think a balanced advertising helps their cause more because if all you say is 90% off, it just sounds like another scam.