Bidding with limited statistical knowledge in online auctions

We consider online auctions from the point of view of a single bidder who has an average budget constraint. By modeling the rest of the bidders through a probability distribution (often referred to as the mean-field approximation), we develop a simple bidding strategy which can be implemented without any statistical knowledge of bids, valuations, and query arrival processes. The key idea is to use stochastic approximation techniques to automatically track long-term averages.