The content published on the site should be useful, unique, and original without excessive advertising, and should have higher payout. Google use to prohibit those arbitrage sites who have scrapped content from other sites, gibberish content that makes no sense or seems auto-generated, duplicate content, or contents unrelated to the topic or business model. The CTR on content websites is generally 30%. Suppose you are buying traffic for 5 cents per click, and you get 100 visitors. The amount spent is $5. The 30% CTR means 30 clicks. The EPC (Earning per Click) is $.80. With 30 clicks, the income is around $24. The good quality content would increase the relevancy of ads and hence help the website to get high paying ads.