PubMatic is a sell-side advertising technology company that operates a programmatic marketplace connecting digital publishers with advertisers. Publishers use PubMatic's platform to monetize ad inventory — across display, video, mobile apps, and CTV — by auctioning that inventory to buyers in real time. On the demand side, PubMatic works with DSPs, agency holding companies, and direct advertisers. PubMatic makes money by taking a percentage fee on the value of advertising impressions transacted through its platform. Key revenue drivers include impression volume, CPM mix, and the share of spend flowing through Supply Path Optimization (SPO) deals — direct arrangements with agencies and advertisers that route committed ad budgets through PubMatic in exchange for custom data workflows and pricing. SPO represented over 55% of platform activity in 2025. CTV is PubMatic's fastest-growing format, reaching roughly 20% of revenue, and PubMatic works with over 90% of the top 30 global streamers. Beyond its core SSP business, PubMatic is building higher-margin revenue streams through Activate, a direct-to-supply buying platform that lets advertisers transact inside PubMatic's SSP without a DSP intermediary; Connect, a sell-side data curation platform; and Convert, a commerce media solution. PubMatic owns and operates its own global data center infrastructure rather than relying on public cloud, which management argues lowers per-unit costs and improves bid response times. A notable concentration risk exists on the demand side, as Google and The Trade Desk together represent roughly half of all ad spend on the platform.