Let&#x27;s assume Theory B is correct, and searching for a faucet and then stopping can be treated as having bought a faucet. That tells the advertiser that the user buys faucets, and that&#x27;s <i>exactly</i> the right person to advertise to. I&#x27;d bet that in a large number of cases someone who buys a faucet is likely to buy another faucet in the near future - faucets are something that you buy when you&#x27;re doing up a house, or you&#x27;ve moved house, etc.<p>Advertising to someone who you have reason to believe is going to buy your product is much more effective than advertising to an unknown person.