The advertiser pays you to get clicks and that clicks must sell! So here is the deal, if the advertiser doesn't get conversions, he will turn off the ads. So simple. The secret is making commercial appealing content, something like a silent seller that will go inside your visitors minds and make them clicks and buy! A good conversion ratio is around 5% of the clicks. If you want to see how good your website converts I suggest you to try any CPA network such as CJ.