MER (Marketing Efficiency Ratio or media efficiency ratio) is an important metric that measures the overall performance of your ads.
Also known as blended ROAS (Return on Ad Spend), or ecosystem ROAS, MER is a broad metric that helps you understand marketing costs as a multiplier of revenue generation. Very broadly put, it is your total revenue divided by your total ad spend.
Why is MER an important metric for advertisers?
An important North Star metric, it is not supposed to guide media-buying decisions at the ad or campaign level.
Rather, it is important to calculate how efficiently you are spending your ad dollars, and when additional spend stops making you additional dollars.
Like ROAS, it is expressed as a ratio.
