Standard mechanism design begins with a statement of the problem, including knowledge on the designer's part about the distribution of the characteristics (preferences and information) of the participants who are to engage with the mechanism. There is a large literature on robust mechanism design, much of which aims to reduce the assumed information the designer has about the participants. In this paper we provide an auction mechanism that reduces the assumed information assumed of the seller, and, in addition, relaxes substantially the assumed information of the participants. In particular, the mechanism performs well when there are many buyers, even though there is no prior distribution over the accuracy of buyers' information on the part of the designer or the participants.