Google AdWords
https://www.forbes.com/sites/quora/2014/08/15/how-exactly-does-google-adwords-work/#74641ded7bd3
This article is about how Google AdWords works. When a person Googles something, an AdWords auction starts with all of the companies that have keywords to match the search as the bidders. Whichever company has the highest AdRank wins the top spot, and the second wins the second spot, and so on. (AdRank is the quality score times the bid of the company.) The company pays the lowest price in order to beat the spot below no matter what they bid.
This article is very applicable to our recent lectures about ads and our past lectures about auctions. In lecture, we learned about how ads are sold and where the price comes from. Often it comes from bidding, as in Google AdWords. Google AdWords essentially uses a second price auction, companies bid values, and the winner of the auction pays the second highest bid.