I don't know exactly how people generate these lists, probably based on adwords estimations. However, it is hard for me to believe that you could get $30+ from a single click. And even if you try to optimize your page, it's impossible to predict which ads will google show on your website. With PPC programs, you can simply show the first bids ads, but on adsense the algo behind it's complicated and unpredictable and I think it's a bad idea to try to manipulate the adsense engine, you could get banned maybe.
Anyway, here are some sites which offer free lists: