What is Backfill?
Backfill is a feature that automatically connects multiple ad sources to fill gaps when there are no high-priced direct deal ad bookings, ensuring continuous ad delivery. Combined with Adrop’s unique bidding and waterfall optimization technology, it simultaneously increases ad pricing (eCPM) and Fill Rate while providing more stable revenue growth.- Automatically connects multiple global ad sources
- Optimizes pricing through Adrop’s unique bidding and waterfall optimization strategy
- Secures optimal pricing (eCPM) and Fill Rate by country, placement, and time zone
- Applies after periodic performance A/B testing
The key is to continuously increase overall eCPM while growing direct ad proportion. Ad Control allows you to manage this process on a single platform.
Why Do You Need Backfill?
Direct Ads Alone Have Limitations
Direct deals have high pricing but struggle to fill all inventory.Network Ads Alone Are Also Insufficient
Network ads like AdMob and AppLovin fill empty inventory, but pricing has limits no matter how optimized. Competition among network ads alone cannot dramatically increase eCPM.True Monetization Is Their Combination
| Ad Type | Advantages | Disadvantages |
|---|---|---|
| Direct Ads | High pricing | Fill Rate limitations |
| Network Ads | High Fill Rate | Pricing limitations |
| Direct + Backfill | High Pricing + High Fill Rate | - |
How It Works
Direct ads display first, and Backfill ads only display when there are no direct ads. You can monetize even empty inventory while protecting direct ad revenue.
Activating
Start Ad Monetization
Turn on Backfill Ads in Console
In the Ad Unit menu, click the ‘Turn on Backfill Ads’ button for the unit you want to start ad monetization.
Update SDK
If you’re not using the latest SDK, you’ll need help from a developer to update for Backfill feature usage.
Setup Guide →
Add ads.txt File
This is a method to certify that your ad placement is safe inventory, and needs to be added only once per app. If you’ve already added ads.txt, there’s nothing additional to do.
Setup Guide →
Upon first activation request, a representative will contact you for optimized operation of direct and Backfill ads.
Pause Ad Monetization
Backfill ads can be paused and restarted at any time.- Status changes are reflected within maximum 30 minutes.
- Does not affect direct ad campaigns.
Turn Off Ad Monetization
You can completely delete Backfill integration info and turn off Backfill ads.Supported Ad Types
Check the supported ad units by format and development environment for ad units created in the console.| Ad Format | Native App | Web (WebView Mobile App) | Notes |
|---|---|---|---|
| Banner | Y | Y | |
| Interstitial | Y | Y | |
| Rewarded Video | N | N | |
| Native | Y | Y | For web environments, supported as full image banner format fitted to container area. |
| Popup | N | N | If you want Backfill for popups, we recommend implementing popups through banner ad units. |
| Splash | N | N |
Native Ad Specifics
- In native app environments, ads are served using ad fields. For optimal monetization, please use all available fields.
- Available ad fields: Advertiser logo, Advertiser name, Call-to-Action (CTA) button, Ad title, Ad description
- Note: Some fields may not be displayed depending on the creative assets prepared by the advertiser.
- In web environments, native ad fields are not used, and ads are served as banners fitted to the entire ad area specification.
WebView Mobile App Environment Specifics
Site Approval: Backfill ad monetization is only possible after ad network site approval is completed. Review may be rejected in the following cases:- When the top-level domain has insufficient content
- When sitemap is not configured
Ad Quality Management
Since Backfill ads are monetized through real-time bidding from various ad networks, pre-screening of creatives is not possible unlike direct ads. Adrop provides safe ad monetization services by automatically blocking sensitive categories and conducting regular/irregular creative quality monitoring and improvement work.- Automatic Sensitive Category Blocking
- Adult content
- Direct sexual references
- Social casino games
- Gambling and betting
- Creative Quality Monitoring
Custom Blocking Options
If you have additional categories or advertiser lists you’d like to block, please submit them using the method below.Submission Method
Make a Copy of Template File
Please make a copy of this template file.
Create Blocking List
Please create your blocking list.
- General category blocking: Set to Blocked
- Sensitive category blocking: Set to Blocked
- Advertiser blocking: Enter the top-level domain URL of advertisers
Submit File
Submit the completed file to contact@adrop.io.
Checking Backfill Performance and Revenue
You can check ad performance and revenue in the Reports > Backfill tab.| Metric | Description |
|---|---|
| Impressions | Number of times ads were actually displayed on user screens |
| Clicks | Number of times users clicked on ads |
| CTR | Rate of clicks among ad impressions |
| CPC | Ad revenue per 1 click |
| CPM | Revenue per 1,000 ad impressions |
| Revenue | Final ad revenue after Adrop commission deduction |
Report Update Cycle
Backfill reports are automatically updated every 6 hours and may take up to 24 hours to reflect the latest data.Segments
By selecting Segment > View by Unit, you can check performance by unit.Export
You can export files via email by clicking CSV Export.Next Steps
Ad Product Settings
Check how to bundle Ad Units to sell as Ad Products.
FAQ
What happens to existing Backfill ads when direct ads come in?
What happens to existing Backfill ads when direct ads come in?
Direct ads automatically display first, and Backfill only fills inventory without direct ads. No manual switching work required. With other solutions, developers must modify code each time direct ads come in, but Ad Control automatically coordinates direct ads and Backfill within a single Ad Unit.
Can I use it together with other network ads?
Can I use it together with other network ads?
Not recommended. Unifying with Ad Control Ad Units allows real-time switching between direct ads and network ads to maximize revenue. Mixing multiple solutions consumes unnecessary resources in operations and development, and you can’t enjoy the benefits of integrated reporting and optimization. To seriously expand your ad business, managing direct ads and Backfill together on one platform is efficient.
Direct ad sales are difficult - can I use only Backfill first?
Direct ad sales are difficult - can I use only Backfill first?
Actually recommended. Start monetization with Backfill first while accumulating traffic data. This data becomes powerful negotiation material during direct ad sales. Once advertisers are secured, just register Ad Products in Console. You can switch to direct ad monetization immediately without separate development.
Why are direct ad prices much higher than Backfill?
Why are direct ad prices much higher than Backfill?
Network ads have pricing limits because they receive ads displayed simultaneously on multiple apps through auction. In contrast, direct ads can receive premium pricing as advertisers purchase specific apps and placements. Securing base revenue with Backfill while increasing direct ad proportion is the key to revenue maximization.