Mobile in-app advertising formats for mobile in-app monetization are the new must-try ad dimensions that seized the digital advertising market in a landslide. In 2017, the overall mobile ad expenditure grew to stunning $49.9 billions and that’s thrice more than was forecasted by Juniper research and industry experts a few years ago.

Meanwhile, after taking a little peek into the future and doing a little math we'll see that mobile web formats are not only destined to stay on the edge of glory but also surpass the boldest growth expectations. According to the IAB report (May 10, 2018), mobile ad units expenditures grow by 36% yearly, given this, we can expect around 67,9 billion by the end of 2018.

With over 90% of Facebook’s ad profits coming from mobile platforms it’s hard to understate the importance of the correctly tuned and robust strategy for mobile ad units. Naturally, every developer and publisher wants to know what is the best mobile ad sizes that surpass all others in the ability to generate revenues, click through rates, or CTRs.

The reality is trickier, there’s no universal or standard mobile ad size or magic mobile advertising format that works equally perfect on all types of platforms or devices. Nothing will give the better impression on ad unit performance than particular in-app ad type testing but we can give it a good starting point.

Best mobile advertising formats: Who’s been playing good?

There are 2 types of common mobile ad formats which displayed impeccable monetization performance within the past few years, - in-app ad format and mobile ads.

Also, it might be interesting to read our article about "The future of mobile ads".

The paid-for advertisement was the first in the list of mobile ad units which made it possible for the app devs monetize the apps before in-app advertising format was delivered by Apple in 2009, superseding the others and snatching over 50% income on the mobile market.

As time passed, mobiles became customary for users, the mobile advertising faced massive changes due to the fact, that users behavior changed drastically.

Instead of installing new applications and Internet surfing, user attention now focused on fewer apps that had all necessary function in-built. Understanding that, developers moved to in-app ad format surroundings that suggested such attractive mobile advertising formats as social, display ads, video ad format, social, and others.

The search ad types alone brought in over $14 billion last year according to BusinessInsider with social and display ads that come just after.


When we talk about standard IAB mobile ad sizes, there’s no need to dig deep into analytics to notice that larger mobile banner sizes became the prevalent ones within past few years. The following graph demonstrates their average click per mille growth reaching 152% record with following 57% average CTR enhancement within past 5 years, according to MoPub.


Best mobile ad formats: which ones work for you?

Regarding certain mobile ad unit size does not totally come down to following latest trends or regarding only ad types that generate exceptionally good revenues to other mobile app developers or publishers, it’s more about selecting good quality ad network. Worth to mention that certain ad networks specialize in certain best mobile ad formats only while others can work with different ones.

Additional questions to ask yourself about determining the best mobile ad size:

  • Who is the target audience of the app? When and how they normally interact with mobile or tablet applications?
  • For how long do you plan running your ad campaign? The mobile advertising ad sizes and units are differentiated according to the stage of your campaign: awareness, consideration, or maybe conversion?
  • How will you select the mobile platform? According to stats, developers traditionally targeting IOS platform due to slightly higher CTR rates, however, the metrics can different and depend on the country of end users.
  • What is your min. and max. budget for rich media ads?
  • How do you plan to define the metrics for ad formats performance?
  • How exactly will you test mobile ad unit sizes?
  • Which mobile web ad formats and sizes specifics can complement your app, improve bidding and capping?

Mobile Video Ads:


Video ad is a format that can improve not only the conversion of your app but also the retention of users. Taken that average US adult watches approximately 5.5 hours of video content daily, the number of people watching videos on their mobiles is increasing as well.

Video ad belongs to the common mobile display ad sizes which generate better engagement and enhances average eCPM in case the video duration is between 15 to 30 seconds, - sufficient time for memorizing the ad without causing user irritation.

In-app video ad is generally performing better (14.0%) than the mobile video ad (8.3%) that, however, doesn’t impact the completion rate dramatically that stays equal for both variants.

The pros and cons of video ads:

Some experts consider video ad formats to be the best mobile ad units that better generate conversion and engagement among users, however, this variant can be costly and there’s always a chance that users skip the advertisement if they don’t like it.

Mobile Banner Ads

mobile-banner-ad-sizeMobile banner is an increasingly popular advertising format the shape of which can be ranged from animated to static images popping up at the user’s screen while browsing the site or at the certain stage of application usage.

The banner usually appears from various corners of the device screen and such mobile ad unit is traditionally the simplest one in terms of implementation. Using banner ad formats is relatively cheap that makes them a good pick for the companies who want to increase brand awareness. Stats say that lifestyle brands can expect highest conversion rates from mobile banner units (2%) on Android when the IOS platform delivers the best results for classified content (3%). The best mobile banner ad sizes are 350*50 and 300*50 for the mobile device.

Regarding the standard mobile banner sizes, the company should remember about the quality of the design to make it fresh in order to avoid so-called banner blindness effect caused by the massive popularity of banner ads

The pros and cons of banner ads:

Banner ads can be good for starting fast and flexible ad campaign, at the same time, they’re quickly falling off the radar as many companies now can afford more eye-catching, sophisticated types of mobile ads.

Mobile Interstitial Ads


Interstitial ads offer different dimensions that build an immersive user experience thanks to the new mobile display ad sizes stretching on the whole user screen. User’s behavior is what triggers these mobile ads, these ads pop up in the moment the person opens the app, navigates it or simply switches among the pages or modes.

With their typical size of 320 x 480px, interstitial ads cover the full screen of the user catching attention at best. If you’re thinking about launching a game or any other sort of app including passing several game levels, this option can be the best mobile ad size.

If to believe InMobi research, interstitial ads came winners in battle with banners, generating the CTRs that are much higher and bringing 70% revenue share from all mobile as a market.

The pros and cons of interstitial ads:

A standard interstitial size can deliver an immersive ad to the end user, both publishers and developer of the app can stay confident - their ad will be seen, at the same time, such ad requires high-level design implementation and the users can grow more irritated from them.

Native Ads

native-adsNative ads are easily integrated ad units, they integrate with application’s content with the help of the icons or the brief description placement. Native ad belongs to the list of popular mobile ad sizes and formats which don’t heavily affect the user’s comfort because they come up harmonized with the rest of the textual or video content.

Native ad is oftentimes called the best mobile ad format due to its proved efficiency to generate 53% more views than banner ads, and in fact, many users (32%) report to be ready to share the native ad content with friends or relatives because those mobile advertising formats known to be often confused with the actual website content.

The pros and cons of native ads:

Native advertising puts a full control over the creatives and ad campaign timing in the developers’ hands, such mobile ad unit is also seen by the users as a normal part of the content, however, mobile ad units like these demand outstanding design to blend with the surrounding content.

Rich Media Ads


Rich media offer the playground for various adapted graphic advertising messages displayed on the mobile device. Rich media ad formats can exist not only within the app ecosystem but also on website versions adapted for mobiles.

Standard and drop-down mobile ad units are considered the ones most popular among advertisers, however, different formats of rich media ads for display advertising are designed to achieve different purposes. The expandable ad is quite popular rich media format that is good at banner blindness removal. Some studies from IAB suggest them to be 25% more memorable than other mobile advertisements.

The pros and cons of rich media ads:

With the help of expandable ads, its is easy to overcome the banner blindness syndrome but it is also important to avoid user frustration using expandable rich media ads. The practice also shows, watching the ad size on mobile the users might not always guess they need to click on it to expand.

Mobile ad units vs. app types

Industry experts claim, in-app and mobile advertising is a proven way to make free apps profitable, only 10% of users are inclined to commit in-app purchases so the remaining 90% are normally monetized with video ads, banners, and other types.

In-app ads help to diversify the risks: even if your application loses its former position in the store or no longer attracts new users, you will still earn from monetizing on existing ones.

Common mobile in-app advertising will be equally effective for the apps brimming with users with impressive daily session duration and the ones that only used occasionally in case the mobile ad unit size and placement has been chosen wisely.

With a correct format and placement, the user doesn’t get annoyed. If your app was free option a long time consider showing mobile ads to new users exceptionally, integrate SDKs that don’t slow down the experience users got used to.

Learn more about new opportunities with SmartyAds Mobile Ad Formats.

SmartyAds SDK is a lightweight option that helps developers integrate best performing mobile advertising sizes and formats without losing sacred app performance quality. For publishers there’s an opportunity to work with several ad networks, reaching multiple SSPs at once. In case choosing the ad unit is bound to the stage of your ad campaign you can switch between them, easily integrating several best mobile ad formats at the same time.

Register at SmartyAds SSP and connect your app to endless monetization opportunities.

Written by
Irina Kovalenko, CMO of SmartyAds
June 2018