C1X is a Silicon Valley-based digital advertising and marketing technology company that is building exactly what the company name suggests - A "Class One Exchange"​ for premium advertisers, advertising agencies and premium publishers.

The digital advertising and marketing industries have faced issues such as lack of transparency, inefficient manual workflow and fragmentation.

C1X is a full-stack advertising and marketing technology platform that provides the ideal set of tools and technologies in an integrated, intuitive user interface that allows for advertisers and marketers to find the audiences and premium inventory that they want to buy, transact on the platform in an efficient manner, and receive actionable insights that can be put to use immediately to increase the performance of the advertising/marketing campaign.

For example, C1X provides its header tag solution which not only allows for the latest header bidding technology, but also provides proprietary C1X features that allow for other intelligent transaction methods that allow for buyers to purchase the exact audiences that they want to purchase on premium sites, and publishers to maximize their monetization through the full-stack yield maximization solution that C1X provides.

C1X also provides features that are tailored specifically towards eCommerce marketplaces and merchants, with a fully-automated native eCommerce ad server suite that allows for marketplace operators to create a new, steady flow of significant advertising revenue, and for merchants to increase their revenue through data-driven promotion of their own products and services.

C1X operates in the United States, India, Japan, Asia Pacific and the Middles East, with plans to expand operations to Europe and South America in 2017.