• July 6, 2021

eCPM, rCPM, and Fill Rate – everything you should know

eCPM, rCPM, and Fill Rate – everything you should know

eCPM, rCPM, and Fill Rate – everything you should know 1024 576 DataLit

As digital advertisers, we attempt to assess the money we can generate from our advertising campaigns and each one of these metrics gives us an alternate point of view and insights into where our money is generated, and from what sources to be precise. Moreover, the digital advertising space is loaded up with technical phrases and long abbreviations intended to add a little spice to your workload – such as eCPM, rCPM, and Fill Rate.

What does any of these mean? Is there a difference? Furthermore, which one would should you be focusing on as a digital advertiser? In this blog, we discuss each one of these metrics and determine what factors are most likely to affect these metrics – for the better or worse.

What’s eCPM?

eCPM is the short form of Effective Cost-per-mile (here mile represents thousand). It is calculated to demonstrate the ad income created from 1000 ad impressions. eCPM is the average number of various CPMs. In a simpler explanation, eCPM gives you the combined average of all bids placed by advertisers on your ad impressions.

This metric shows us how much money we generate for 1000 sold impressions. It’s a very helpful factor, as it shows how costly or cheap we sell our impressions. Regardless, it doesn’t reveal to us much about the effectiveness of our ad.

What’s rCPM?

rCPM stands for Real Cost-per-mile or otherwise called revenue CPM. The estimation of rCPM shows how much ad income the publishers created from ad requests. Remember that ad impressions and ad requests are two different things and vary. An ad request is at whatever point your website requires an advertisement to be shown on it. It doesn’t mean that the ad will naturally be visible on your website. Then again, ad impression, however, occurs right after the bid for the advertisement is approved and the ad is visible on your website.

What’s Fill Rate?

Fill Rate is a percentage of the entirety of the publisher’s ad requests sold. Fill rate is considered by various advertisers as a sign of their success, because of the deception that selling all your stock will generate the most elevated income for you. Shockingly, selling as many impressions as would be possible doesn’t create the maximum possible income. Eventually, this may just mean that you are selling at minimal prices and losing money somehow.

Factors that influence these metrics


This is a primary and key factor that can turn around things on its own. Without users, we would not have anybody to show the ads to, however, users are just an obligation to some extent since they can incredibly change as far as their ad value. Some of them make only a couple of page views, while others can go up to 20 times. Eventually, they can decide to enable cookies or not. Because retargeting is hugely beneficial from a digital advertiser’s perspective, cookies can have a massive effect.

Page Views

This factor is more relevant to the estimation of our expected effectiveness, however not totally. Various publishers imagine that the more page views they have, the more they should be earning. They hope to have somewhat same or growing RPM but page views can vary from case to case. A page view can be generated from a website without any advertisements, where there are no ad requests to sell. It very well may be from a mobile website, where, generally, there are up to three ad requests. It can have its sources from a desktop website with even five ad requests too.

Ad Requests

Considering all the above-mentioned factors, this is a pivotal factor – one ad request is an opportunity to sell one advertisement. You will not see huge differences in ad request values not like in the case of users or page views; in any case, don’t expect ad requests to consistently have a similar value every time.

Don’t Limit Your Ad Evaluation!

While it’s important to know your eCPM and rCPM, the assessment of your ad performance by these factors alone is somewhat obsolete. Indeed, these metrics say nothing regarding how precisely you bring in money. Remember that these are just comparative figures, the total number of impressions can impact them massively. Hence, these aren’t appropriate for evaluating your ad performance or making an ad forecast. To assess the viability of a given advertisement, you’ll need to jump further into metrics and information.

For instance, make sure to compare your eCPM rate with Fill Rate. An optimal fill rate is 100% that implies that all of the ads your application mentioned were delivered and shown. However, a 100% fill rate is hard to accomplish because of various factors – such as poor connection, low battery, or a weak network. Then again, the fill rate shouldn’t be excessively low. Even if your eCPM rate is high, a low fill rate can be the reason for low ad revenue, so you should consider them together to improve your overall ad revenue.