PPC arbitrage is when you use PPC to drive traffic to your site whose content is mostly other PPC ads. The idea is to make money off people clicking ads on your site by buying the keywords that trigger those ads on your site at a cheaper rate. This doesn't work for many reasons and should be obvious why. First, you need good content on your site and for the keywords you bid on. If you bid on keywords that have nothing to do with your page content, you get a quality penalty which drives your costs up. Second, visitors will not be too happy to come to a site full of ads and leave just as quickly as they came. Google may even slap you for this. Third, even with good content, you will not likely get a high enough percentage of visitors to click on ads to make up the difference in what you pay. It's a losing proposition. The percentage of people clicking on ads is only a few percentage. Let's put it at 10% those who click on one or two ads, which is probably typical but I think I'm liberal with that number. You might get only five cents a click, say ten cents total if each clicked two ads. That would be revenues of $1 for every 100 visitor. This means you need to get traffic at just one cent a click or less. The numbers don't add up.
Google is not allowing for PPC arbitrage. Many people get blocked adsense and adwords accounts last days because of that.
It's the garbitrage that I was referring to. I guess to me, ppc arbitrage has become synonymous with the practice you describe! I agree that providing good content, with Adsense, whatever on the side, is fine and often provides nice returns for the advertisers. I have commented before that we get good results from the Adwords content program. The site exclusion tool there is a plus.
PPC arbitrage is no more....but few people are struggling in this business and also making good money...i had done that before and had a great experience coz my bank account was happy