Paid Placement: Advertising and Search on the Internet
研究了广告主通过竞价获得搜索引擎关键词排名位置的付费排名模式，发现该模式能揭示产品相关性，引导消费者高效搜索并提升总产出。
Paid placement, where advertisers bid payments to a search engine to\nhave their products appear next to keyword search results, has emerged\nas a predominant form of advertising on the Internet. This paper studies\na product-di¤erentiation model where consumers are initially\nuncertain about the desirability of and valuation for di¤erent\nsellers products, and can learn about a seller s product through a\ncostly search. In equilibrium, a seller bids more for placement when his\nproduct is more relevant for a given keyword, and the paid placement of\nsellers by the search engine reveals information about the relevance of\ntheir products. This results in e¢ cient (sequential) search by\nconsumers and increases total output.