What is the initial document sent by an advertiser inviting a publisher to propose an advertising campaign?

The initial document that an advertiser sends to a publisher to invite proposals for an advertising campaign is known as a Request for Proposal (RFP). An RFP is a formal invitation that outlines the advertiser's needs and objectives for the campaign, including details such as budget, preferred formats, target audience, and timelines. This document serves as a foundation for communication between the advertiser and the publisher, allowing the publisher to craft a tailored proposal that aligns with the advertiser's goals.

Using an RFP process, advertisers can compare different publishers' proposals, which helps in making informed decisions about which advertising partners to work with. It fosters a competitive environment where publishers must present their best ideas and pricing to attract the advertiser's business. This structured approach ensures clarity and efficiency in the collaboration process.

In contrast, an ad tag relates to the technical implementation of advertising and does not serve the purpose of initiating a campaign proposal. Terms and conditions typically outline the legal and operational framework of the partnership rather than initiate it. An ad exchange is a digital marketplace that facilitates the buying and selling of online ad inventory, not a document used to propose advertising campaigns.