If you are running AppLovin MAX or Unity LevelPlay as your mediation platform, you already have access to a solid set of built-in ad networks. But the real revenue gains come when you add custom demand sources that increase competition for every impression. Here is how to do it effectively.
Why Add Custom Demand?
Every mediation platform comes with a default set of ad networks. These are the networks that have formal SDK integrations with the platform. But there is a much larger universe of demand out there — managed demand partners, regional ad networks, and direct advertiser relationships that can fill gaps in your waterfall and push your eCPMs higher.
The math is simple: more bidders competing for each impression means higher winning bids. Adding even one well-positioned custom demand source can lift overall revenue by 15 to 30 percent.
Adding Custom Demand to AppLovin MAX
AppLovin MAX supports custom network adapters that let you integrate any demand source into your waterfall. The process involves three steps:
Step 1: Create a Custom Network
In the MAX dashboard, navigate to Mediation and select Manage Networks. Add a new custom network and configure the class name and adapter that your demand partner provides. This adapter handles the communication between MAX and the demand source.
Step 2: Configure Ad Units
For each ad unit (banner, interstitial, rewarded), add the custom network as a demand source. Set the expected eCPM so MAX can position it correctly in the waterfall. Your demand partner should provide guidance on competitive floor prices for your specific geo and format mix.
Step 3: Test and Optimize
Start with a limited rollout — perhaps 10 percent of traffic — to validate that the integration is working correctly and that the reported eCPMs match expectations. Once confirmed, gradually increase the traffic allocation while monitoring fill rate and latency.
Adding Custom Demand to Unity LevelPlay
Unity LevelPlay (formerly ironSource) follows a similar pattern but with its own terminology and dashboard flow:
Step 1: Set Up a Custom Adapter
LevelPlay supports custom adapters through its SDK. Your demand partner provides an adapter module that you include in your app alongside the LevelPlay SDK. Register the adapter in the LevelPlay dashboard under the Networks section.
Step 2: Define Instances
Create instances for each ad format you want to serve through the custom demand source. Each instance maps to a specific ad unit on the demand side. Configure the expected CPM for proper waterfall positioning.
Step 3: Waterfall Positioning
Place your custom demand at an appropriate position in the waterfall. Too high and it may cause latency if it does not fill quickly; too low and it will rarely get a chance to compete. Start in the middle of your waterfall and adjust based on actual performance data.
The best waterfall position for custom demand is typically just below your top two performing networks. This ensures it gets meaningful traffic while not disrupting your highest earners.
Best Practices
Monitor Latency
Custom demand sources add an additional ad call to your waterfall. Monitor the time-to-fill metric closely. If a custom source is adding more than 200 milliseconds to your average ad load time, consider adjusting its timeout settings or waterfall position.
Use A/B Testing
Both MAX and LevelPlay support A/B testing of waterfall configurations. Use this to compare your current waterfall against a variant that includes the custom demand source. Let the data tell you whether it is actually lifting revenue.
Work With a Managed Partner
The technical integration is just the beginning. Ongoing optimization — adjusting floor prices, monitoring fill rates, rotating underperforming sources — is where the real value lies. A managed demand partner handles all of this, providing you with a single integration point and continuous optimization without requiring your team to become waterfall experts.
Getting Started
If you want to add custom demand to your waterfall but do not want to manage the complexity yourself, reach out to a managed monetization partner. They provide the adapter, handle the configuration, and continuously optimize the integration — so you get higher revenue with minimal engineering effort.