The primary goal is to build a large Custom Audience composed of website visitors for future retargeting. The Traffic objective is specifically designed to drive the maximum number of people to a destination, such as a website. Meta's ad delivery system will optimize a Traffic campaign to find users most likely to click a link and visit the landing page, thereby maximizing the pool of visitors from which to create the Custom Audience. While a Conversions campaign also sends users to a website, it optimizes for a smaller, more specific group of people likely to perform a valuable action (e.g., purchase), which would not fulfill the requirement of creating the largest possible audience.

A. Conversions: This objective optimizes for valuable actions on a website, targeting a smaller, more qualified audience, which contradicts the goal of building a large visitor pool.

B. Leads: This objective is optimized for collecting contact information through forms, not for maximizing the general volume of website visitors.

C. Engagement: This objective is optimized for on-platform interactions like post likes, comments, and shares, and does not prioritize sending users to an external website.

1. Meta Business Help Center, "About ad objectives": This official documentation outlines the purpose of each campaign objective. It states, "The Traffic objective is designed to drive people to a destination, such as a website, app, or Facebook event." This directly supports its use for maximizing website visitors. In contrast, it defines the Conversions objective as being "designed to prompt people to take a valuable action on your website, in your app, or in Messenger."

Source: Meta Business Help Center, Article ID: aBu3TRBEtDEyHyE.

2. Meta Blueprint, Course: "Choose an Ad Objective": This course explains that the Traffic objective should be used when the goal is to "send people from ads to any destination, like your website, app or Messenger conversation." It clarifies that this objective is ideal for increasing the number of visitors to a specific page, which is the foundational step for creating a website visitor Custom Audience.

Source: Meta Blueprint, Learning Program: "Advertise with Meta," Course: "Choose an Ad Objective," Section: "Consideration."