Michael Ostrovsky (Stanford GSB) and Michael Schwarz (Yahoo! Research) helped Yahoo! to improve its click price per ad. Yahoo! was charging 10c/click. Ostrovsky and Schwarz ran some field experiments:

Reserve prices in the randomly selected “treatment” group were set
based on the guidance provided by the theory of optimal auctions, while in the “control” group
they were left at the old level of 10 cents per click. The revenues in the treatment group have
increased substantially relative to the control group, showing that reserve prices in auctions can in
fact play an important role and that theory provides a useful guide for setting them.

It seems they made money for Yahoo!:

We conclude with a quote from a Yahoo! executive, describing the overall impact of
improved reserve prices on company revenues.
On the [revenue per search] front I mentioned we grew 11% year-over-year in the quarter
[. . . ], so thats north of a 20% gap search growth rate in the US and that is a factor of,
attributed to rolling out a number of the product upgrades we’ve been doing. [Market
Reserve Pricing] was probably the most signi cant in terms of its impact in the quarter.
We had a full quarter impact of that in Q3, but we still have the bene t of rolling that
around the world.
Sue Decker, President, Yahoo! Inc. Q3 2008 Earnings Call.

But it seems Yahoo! is eliminating the entire research group in its downsizing, including I suppose Michael Schwarz. Preston McAfee had already left for Google Research. I hope others also have a soft landing.