Using both a lab experiment and actual transaction data, we investigated whether and how incidental similarities (e.g., shared letters between buyer and seller's name) might influence buyer behavior. Particularly, while prior work suggests that consumers generally prefer incidental similarity, we use the context of Internet auctions to show that this preference reverses when prices are high. Under these conditions, buyers avoid incidentally similar sellers. We speculate that this effect is tied to individuals' motive to self‐protect. Implications for theory and practice are discussed.