An advertiser is a person or organization that creates and pays for advertisements. Advertisers are typically businesses or organizations that want to promote their products, services, or ideas to potential customers or supporters. Advertisers use various forms of advertising, such as television commercials, print ads, radio spots, and online ads, to reach their desired audience and to persuade them to take a specific action, such as purchasing a product or supporting a cause.

Advertisers typically work with advertising agencies and other partners to develop and execute their advertising campaigns. Advertisers use various tools and techniques to target their ads to the right audience, to measure the performance of their ads, and to optimize their campaigns for maximum effectiveness. Advertisers are an essential part of the online advertising ecosystem, as they provide the demand for ad inventory, and they drive the innovation and growth of the digital advertising industry.