A marketing agency is a service provider that helps businesses use marketing to reach, nurture, and convert users. Marketing agencies vary widely in size, specialty, and services.

A digital marketing agency is a company that deals exclusively in marketing to consumers or businesses through digital channels. This includes creating and launching campaigns for clients through social media, pay-per-click advertising, videos, and custom websites, among other means.

Online advertising agencies promote their clients' brands, products, and services, using digital marketing tactics. They offer services such as PPC services, content marketing services, and SEO services.