Magnite operates a sell-side advertising platform (SSP) that connects digital publishers — streaming services, apps, and websites — with buyers like brands, agencies, and demand-side platforms (DSPs). Publishers use Magnite's platform to manage and monetize their ad inventory; buyers use it to access that inventory at scale. Magnite runs the auction infrastructure in the middle and earns a take rate on the ad spend that flows through its platform. The core financial metric is contribution ex-TAC, which strips out pass-through payments to publishers. Magnite's primary focus is CTV, where it operates SpringServe — a purpose-built programmatic SSP and ad server for streaming. Major streaming publishers including Roku, Netflix, Disney, Warner Bros. Discovery, and LG use SpringServe to manage their full CTV ad stack, including ad podding, dynamic ad insertion for live events, and yield optimization. CTV is the faster-growing business and represented roughly 45% of contribution ex-TAC in Q3 2025. The second business, DV+ (desktop and mobile display, video, and audio), is more commoditized and represented the remaining 55%. Magnite's take rate is higher on biddable open-market auctions than on programmatic guaranteed deals, so as CTV inventory shifts toward biddable transactions, take rates should improve. Magnite is also shifting CTV infrastructure from cloud to owned data centers to reduce per-unit costs. Growth initiatives include expanding CTV inventory and live sports programmatic, building SMB advertiser access via its Streamr.ai acquisition, and running agency-branded curated marketplaces through its ClearLine self-service product.