What this data shows is that when you set you campaigns for Max CPA bidding, Google Adwords may immediately rule out certain keywords or websites because it doesn't want to risk going over the CPA you set. When you use Target CPA bidding, you give Google Adwords permission to bid above the CPA you set so long as you end up at an average that is in line with it. So, with the click of a mouse we were able open the funnel that much wider, doubling and tripling volume, while keeping our costs in check. Now that's what we call efficiency!