Several months ago I discussed a few really important cost control levers in Facebook - bid cap, cost cap and target cost [see http://www.amberfoxworth.com/anti-blog/there-s-a-new-cap-in-town]. All of which help you control how much you're spending on ads. Welll there's another new cap in town!!!! Insert drum roll for Min ROAS. This is without a doubt the best of the caps. This cap allows you to set the minimum ROAS (return on ad spend) you would like to achieve and FB will use its learning engine to find the most suitable people to show your ads to. You may notice decreased delivery with this method, so it's not ideal to rely solely on Min ROAS but nevertheless it's a great test and we've seen amazing results on this side. So how do you do it? Create a New Campaign and activate Campaign Budget Optimization. Next, select "Highest Value with Minimum ROAS" as your Campaign Bid Strategy. At the ad set level you will enter the Minimum ROAS you would like to see across your ad sets. DONE!