Internet retailers often make use of price search services (infomediaries) that have the effect of reducing consumer search and expanding seller market presence. Research on price and advertising suggests that this may not be a profitable strategy. We develop an experimental posted-offer market to estimate the impact of infomediaries on price of homogenous goods. We analyze panel data from a range of market conditions that address how infomediaries services affect both seller-level offered price as well as market-level transacted price. We find that, while sellers attempt to extract higher prices through a higher initial offer price when using an infomediary, they fail to successfully collect it; transacted prices remain largely unchanged. ...