A lot of people get all worked up about Google Advertising arbitrage. Arbitrage is simply buying something in a market and selling it in a market at a higher price. Traditionally, arbitrage is completed with financial instrument like foreign currencies. Often this involves buying currency in one area of the world and selling it for a small percentage gain in another part of the world. If you can buy $100 worth of a currency in London for $100 and instantly sell it in Hong Kong for $100.75, you would be wise to buy and sell as much as you could while the arbitrage opportunity existed. I was visiting my sister-in-law one day at a large Asian bank about ten years ago. While I was there several young traders came out of the foreign exchange office celebrating the fact that they had netted a million dollar profit in one day for the first time. Arbitrage is part of business.
In advertising, Google arbitrage is nothing new, it's just advertising arbitrage. We all know that radio stations, TV stations, newspapers, magazines, etc all earn their revenue from advertising sales. We also see newspapers advertising on TV stations, radio stations advertising on bus stops, magazines advertising on TV, etc. These media channels are buying advertising so that they can sell more advertising in other words they are doing advertising arbitrage.
With Google arbitrage, traffic is purchased as Google Adwords traffic and then sold as Google Adsense traffic at a higher eCPM. Google has no problem with this as long as you abide by the Terms of Service (TOS) of both Adwords and Adsense. To abide Adwords TOS you primarily need high quality landing page content and ads that are representative. Typically, the quality of your ads and content will not get you banned but minimum bids can rise to $5 or even $10 per click. To abide by Adsense TOS you need to have good content, need to avoid fraudulent clicks, can't encourage visitors to click on your ads, and a number of other things most of know out of a basic sense right and wrong.
The ultimate argument in this discussion comes from Google. Google has always pushed Adsense users to use all of Google's tools including Adwords. Here is the current log out screen with Adsense. You will note that Google encourages Adsense users to "Drive traffic to your site with Google Adwords. Google is encouraging arbitrage.
Made for Adsense (MFA) pages are often discussed. These are pages that more appropriately should be called content free sites as many high quality sites were made with advertising in mind including the Google search page. Content free pages would include many of the pages you see that have "What you need when you need it" (WYNWYNI) as a motto that show nothing but several blocks of Adsense ads and links to more WYNWYNI pages. These content free pages are what people inappropriately call MFA as both good and bad sites can be made for Adsense.
I agree that Google should weed out the WYNWYNI pages. I disagree that arbitrage should be discouraged as arbitrage is a healthy natural part of business and arbitrage is what forces markets to be efficient.