Dash Stats Docs

# Monetization tips: Understanding your eCPM¶

## What is eCPM? And why is it important?¶

When you show ads in your Android app, you probably want to know how well those ads perform. To generate the most revenue it’s important to determine which ads work the best for your app. What metric can you best use to compare the performance of different ads?

The metric that’s best for comparing different ads is called eCPM. eCPM stands for “effective Cost Per Mille”, in which mille comes from Latin and means 1000. An ad’s eCPM tells you how much revenue you earn when you display the ad a thousand times:

To maximize the revenue you earn from your app, you should show ads with the highest eCPM values. Most ad networks will show you the eCPM in their dashboard. It’s sometimes also referred to as RPM (Revenue Per Mille).

## Why should you use the eCPM instead of the total revenue when comparing ads?¶

Assume that you show ads from two different ad networks in your app. Yesterday you earned \$25 from ad network A and \$30 from ad network B. Based on this revenue, you would say that Ad B works better for your app. But is that really true? Suppose that you showed ads from A 6,000 times, and you showed ads from B 10,000 times. Let’s calculate the eCPM for both ads.

Ad network A: \$ 25 / 6,000 * 1,000 = \$ 4.17

Ad network B: \$ 30 / 10,000 * 1,000 = \$ 3.00

The eCPM of ad network A is \$ 1.17 higher than the eCPM of ad network B. You can use this eCPM to calculate how ad network A would have performed on the impressions served by network B. If the 10,000 impressions that you filled with network B had been filled by network A, you probably would have earned \$41.70 from those, instead of the \$30 that network B made.