Ad auction

Each time someone searches, or clicks a related search on an arbitrage lander, the search engine holds an auction in a fraction of a second. Every advertiser whose keywords match the query is entered. The engine ranks them by Ad Rank, which blends bid and quality, picks the winners for the available slots and sets each one's price. Advertisers pay only when their ad is clicked, and usually pay less than their Maximum CPC bid.

This auction is the source of every cent in search arbitrage. The RPC a publisher receives is the auction price of the clicked ad, minus the search engine's share and the feed provider's share. Competitive queries with many bidders, such as insurance or legal services, clear at high prices. Queries with one bidder, or none, pay little.

That is why arbitrageurs study search intent and verticals so closely: they are trying to send visitors into the most valuable auctions. It also explains volatility. Advertisers change budgets by season, day and hour, and many bid less for search partner clicks if those convert worse, sometimes automatically through smart pricing.

Think of it like this

Picture an auction house running a new sale for every customer who walks in, with the bidders ranked on the quality of their goods as well as their offer.