So now you know your effective CPA for the ad you ran. You can count on a 3.7% install rate. Your app costs $1 For every 100 people who click your ad, 3.7 of t

So now you know your effective CPA for the ad you ran. You can count on a 3.7% install rate. Your app costs $1 For every 100 people who click your ad, 3.7 of them buy it - Making you $3.70 You need to pay less than $3.70 per 100 clicks So set your CPC for that ad at 0.036 and write another, better ad. Want to cut down on spurious clicks? Make sure it's obvious it's a paid app before they click, and make sure you're talking right at what they need/care about