Google AdWords are the single most popular PPC advertising system in the world. The AdWords platform enables businesses to create ads that appear on Google’s search engine and other Google properties.
AdWords operates on a pay-per-click model, in which users bid on keywords and pay for each click on their advertisements. Every time a search is initiated, Google digs into the pool of AdWords advertisers and chooses a set of winners to appear in the valuable ad space on its search results page. The “winners” are chosen based on a combination of factors, including the quality and relevance of their keywords and ad campaigns, as well as the size of their keyword bids.
More specifically, who gets to appear on the page is based on and advertiser’s Ad Rank, a metric calculated by multiplying two key factors – CPC Bid (the highest amount an advertiser is willing to spend) and Quality Score (a value that takes into account your click-through rate, relevance, and landing page quality). This system allows winning advertisers to reach potential customers at a cost that fits their budget. It’s essentially a kind of auction. The below infographic illustrates how this auction system works.