It ranks highly because the content farms target long-tail searches where it's easy for marginal content to dominate the results. They are in a sense arbitrageu

It ranks highly because the content farms target long-tail searches where it's easy for marginal content to dominate the results. They are in a sense arbitrageurs. They use software to located search terms where the revenue from ads outweighs the cost of commissioning and ranking a low-quality page.