Detailed targeting is Meta's system for narrowing an audience by interests, behaviors, and demographics. It is powerful for finding a starting audience, but it is self-declared and increasingly treated by Meta as a suggestion rather than a hard boundary.
What it can and cannot do
Detailed targeting lets you stack interests and behaviors to describe an audience. The limit is that much of it is inferred or self-declared, so it approximates intent rather than proving it. With Advantage+ audience and detailed targeting expansion, Meta may also deliver beyond your selections when it expects better results.
How to use it well
Treat detailed targeting as a seed, not a fence. It is a fine way to bootstrap a cold audience, but the durable signal comes from your pixel and a lookalike of real converters. Over-narrow stacking also shrinks the audience below what the algorithm needs to learn, which can trigger overlap and learning problems.