Google AdSense is the most popular and lucrative advertising program on the net. It's also among the easiest to join (especially on Google's Blogger/Blogspot platform, which lets bloggers seamlessly add customized AdSense widgets).
Each publisher doesn't have to track down advertisers selling products in their particular niche. AdSense's contextual algorithms ensure that relevant ads appear on each page, which drastically increases the chances that readers will be interested in the products, click the ads, and thus generate revenue for the publisher.
A law of one price argument could be made that AdSense can pay lower rates and insist on more demanding terms than could other advertising programs. These other programs must pay higher rates (or offer better terms) to compensate publishers for relative inconvenience of using their services.
Take, for instance, the minimum payment threshold. AdSense will not pay a publisher until he or she has earned $100, while Chitika's and Amazon Associates' minimums are both $10.
A high payout threshold benefits Google in several ways:
(1) Transactions and Accounting Costs
It's cheaper to pay publishers larger amounts less frequently than it is to pay them smaller amounts more frequently. Fewer transactions means lower bank fees and accounting costs.
The time value of money can be calculated from interest rates; in short, $100 today is more valuable than $100 a year from now. If Google paid a publisher $10 every month instead of $120 at the end of the year, he could invest the money along the way and come out with more than $120. Instead, Google keeps the interest, which substantially lowers the cost of making payments when they come due many months down the road.
(3) Small Accounts
Many small Web publishers will give up long before reaching the $100 payment threshold. They may shut down their Web sites, cease to publish new content, or switch to a more lucrative advertising network.
Although a publisher can cancel his relationship with AdSense and receive a payout if his account has earned at least $10, there is an expected 90-day delay before he will see the money (and again, Google is not compensating him for the lost interest).
But not everyone below the threshold who is no longer earning AdSense revenue will cancel. Google's advertisers pay Google for each and every their ads are clicked, but Google will never have to pay some of its AdSense publishers their share because of the hurdles described above.