Character.AI optimizes ad monetization across 1+ hour of daily user engagement with Liftoff Monetize
App category: AI Entertainment / Conversational AI | Solution: Liftoff Monetize | Formats: Banner, Interstitial, Rewarded, App Open | Mediation: Hybrid
- 30%+ higher realized eCPM than other partners during the first 28 days in the mobile interstitial stack, adjusted for platform, country, and calendar day
- By its fourth week live, Liftoff was one of Character.AI’s top three ad partners by realized revenue.
- Expansion from two formats to a hybrid multi-format setup, allowing revenue to scale with engagement rather than ad load
“During its first 28 days in our mobile interstitial stack, Liftoff Monetize delivered more than 30% higher realized eCPM than other partners, after adjusting for platform, country, and calendar day. Alongside that performance, what stood out was Liftoff’s openness. Liftoff understood the balance we wanted between revenue and experience before they started optimizing, and built their approach around our strategy instead of a standard playbook.”
Andy Nahman, Head of Monetization and Data Science, Character.AI
Character.AI is an AI entertainment platform, headquartered in Redwood City, California. While much of the AI industry has focused on utilitarian tools, Character.AI was among the first to prioritize conversational AI and immersive entertainment, giving users a place to express their creativity through fandom, roleplay, and interactive storytelling.
Around 16 million people use Character.AI every month, with users spending an average of more than one hour per day on the platform. This combination of scale and deep engagement creates a significant opportunity for monetization, along with the challenge of introducing ads into an experience designed to keep users immersed.
The challenge: monetizing an experience built on immersion
High-engagement AI products are expensive to run, and unlike traditional media platforms, every single interaction carries a real compute cost. Character.AI already had a robust subscription business, with many users also preferring a free tier. Advertising complements subscriptions by scaling with usage, keeping the core experience broadly available. The harder question was how to introduce it effectively.
Immersion is what makes Character.AI work. A user an hour deep into an unfolding story is not a user who will welcome a poorly timed interruption. Any monetization strategy, therefore, needed to generate meaningful revenue without compromising the experience that keeps users engaged.
The strategy: earn permission first, then diversify format
Before optimizing for yield, Character.AI built user control into its monetization approach. Free users can hide ads or redeem one-hour Ad Free Passes using Charms, either earned in-product or purchased. Subscribers on c.ai+ see no pop-up or banner ads. For compute-heavy features such as Swipes, Go-ons, and Memos, the team introduced usage limits rather than hard paywalls, helping manage infrastructure costs while protecting access to the core chat experience.
Transparency was equally important. Character.AI communicates with its community about why advertising exists, including how it helps fund server costs and keep core chat free, while the team continues to refine ad placement and creative quality.
With that foundation in place, Character.AI turned its attention to demand. Given the size and global distribution of its audience, the company works with many top-tier mobile demand partners, and Liftoff Monetize quickly established itself as one of its top ad revenue contributors. Ease of integration and SDK reliability were also important. For a team shipping at pace, download size, dependency overhead, and reliability all matter. The Vungle SDK proved straightforward to integrate and dependable in production.
The turning point: two formats could not carry a one-hour session
Banner and interstitial placements went live first, and their early performance confirmed that demand was there. Fill and pricing were strong. The bigger question was whether two formats could effectively monetize an app where users spend more than an hour a day without relying too heavily on interruptions.
That performance gave Character.AI the confidence to expand rather than simply increase ad frequency. The team moved toward a hybrid setup where rewarded, interstitial, In-Line, and App Open could each play a different role within the user journey.
The goal was simple: allow revenue to scale with engagement rather than ad load.
The impact: a 30% eCPM premium in the first 28 days
During its first 28 days in Character.AI’s mobile interstitial stack, Liftoff Monetize delivered more than 30% higher realized eCPM than other partners, after adjusting for platform, country, and calendar day. Within roughly a month of going live, Liftoff had also become one of Character.AI’s top ad revenue contributors.
Beyond the early performance, Character.AI valued Liftoff’s collaborative approach. The Liftoff team took time upfront to understand Character.AI’s goals, the balance it wanted to strike between revenue and experience, and how it planned to evolve its format mix. Optimization could then support that strategy rather than follow a standard playbook.
For Character.AI, the experience reinforced an important principle: the best monetization partners adapt to your strategy, not the other way around.
What’s next: In-Line and the earliest days of the journey
Character.AI is looking to scale In-Line Ads as the latest addition to its monetization mix. The format is uniquely suited to the platform’s engagement profile, scaling alongside long sessions without interrupting the flow of a conversation. The team expects it to unlock incremental inventory on its core surface, creating more room to balance overall ad load rather than asking interstitials to carry more of the weight.
Character.AI is still in the early stages of its monetization journey and plans to continue testing ad experiences that help make its AI entertainment technology available to a broad global audience.
For publishers building genuinely immersive products, Character.AI’s approach offers a useful principle: give users control, be transparent about the role of advertising, and use a diverse format mix to scale revenue with engagement rather than frequency.
*Observational comparison. All benchmarks were standardized to Liftoff’s platform-country-day impression mix; this does not estimate incremental or causal lift.