Start.io for Publishers
Delivering hundreds of millions of ads each day to thousands of leading mobile app developers and website publishers.

Start.io helps app developers and publishers generate advertising revenue by connecting their mobile in-app ad inventory to global programmatic demand through its mobile Supply-Side Platform (SSP). Start.io runs real-time bidding (RTB) auctions across thousands of Demand-Side Platforms (DSPs), ad networks, and direct brand buyers, maximizing developer yield while maintaining a strong user experience and high ad-quality standards.

App developers can connect to Start.io using advanced in-app header bidding (in-app bidding) through several integration options: SDK: Start.io's proprietary SDK is the recommended option, ensuring fast ad rendering and optimal targeting. Prebid (Prebid JS / Prebid Server): the open-source framework for running in-app header bidding. Third-party mediation platforms: integrate through official mediation partners such as TopOn, TradePlus, and Yandex, or via a mediation adapter for AdMob, AppLovin, and Unity. Header bidding via Amazon TAM/UAM or Nimbus.

Start.io supports all standard mobile in-app ad formats, optimized for app monetization and user engagement: Video ads Interstitial ads Rewarded video ads Native ads Rich media ads Banner ads (standard and MREC) These formats support both performance advertising and brand advertising.

App-ads.txt (Authorized Digital Sellers for Apps) is an IAB-standard text file you host on your developer website that publicly declares which ad platforms and SSPs are authorized to sell advertising on behalf of your apps. Without it, programmatic buyers—particularly those enforcing strict supply-path optimization (SPO) policies—will filter your inventory out of bid consideration. Adding app-ads.txt directly increases your fill rate, protects your inventory from unauthorized reselling, and qualifies your apps for premium demand from brand-safety-conscious advertisers. Start.io provides the exact line entries to add in the Publisher Dashboard.

Start.io combines mobile monetization infrastructure with large-scale first-party mobile data intelligence. Key differentiators include: Over 100 billion first-party mobile signals analyzed daily Deterministic audience segmentation capabilities Global programmatic demand relationships Unlike traditional ad platforms that focus primarily on ad serving, Start.io also transforms mobile data signals into actionable audience segments for advertisers, agencies, and DSPs running performance and brand campaigns at scale.

Start.io operates a first-party data framework built around explicit user consent and verifiable compliance with global privacy regulations. The platform supports GDPR, CCPA/CPRA, COPPA, and LGPD, among other local regulations. Start.io focuses on responsible first-party data practices, consent-aware monetization workflows, and transparent data handling.

Bid rate is the percentage of ad bid requests that receive a response (bids submitted ÷ bid requests received). The main driver of bid rate is targeting match—whether the impression matches an active campaign's targeting, such as geo, audience segment, device, OS, app category, and daypart. Other factors include inventory quality and brand safety, reseller (app-ads.txt) status, data completeness in the bid request, floor prices, format and size compatibility, auction and timeout dynamics, and budget and pacing.

App developer revenue is calculated on a CPM basis (cost per 1,000 ad impressions). Your earnings reflect the aggregate value of these impressions, net of invalid traffic (IVT) deductions and any applicable adjustments.

Start.io works with a broad range of advertising partners, including direct advertisers, advertising agencies, media-buying platforms, and demand-side platforms (DSPs).

Start.io supports multiple payment methods for developers, subject to a minimum payout threshold, on a NET 45 payment cycle. For onboarding assistance, integration support, or monetization strategy guidance, contact the Start.io team at marketing@start.io.