Lesson 7 of 30 · 9 min
The five signals you can actually buy
Geography, demography, behavior, context, and your own data.
Geography and demography: cheap, blunt, reliable
Location and age or gender brackets are stable and available everywhere, which makes them a safe frame. They are rarely enough on their own: most categories have buyers spread across brackets, so leading with demographics alone usually buys a lot of irrelevant reach.
Behavior and interest: powerful, and decaying
Behavioral segments infer intent from what people did — searched, visited, watched, purchased. They are the strongest third-party signal, but they age quickly. Someone who researched a car six months ago has probably already bought one, so recency windows matter more than segment names.
Context: what the person is doing right now
Contextual targeting places ads against relevant content rather than tracked individuals. It is durable as privacy rules tighten, it needs no personal data, and it aligns the message with a mindset — a roof repair ad next to a storm-damage article is well-timed even with no profile attached.
First-party data: your smallest and best audience
Customer lists, site visitors, and app users are your highest-signal audience, and the only one competitors cannot buy. Use it three ways: retarget, suppress people who already converted, and build lookalikes from your best customers rather than from all customers.
Suppression is targeting
Deciding who not to pay for is as valuable as deciding who to reach. Excluding recent purchasers, current employees, or unqualified geographies quietly improves every efficiency metric in the plan without a single new impression.
Takeaway
Lead with the signal closest to real intent, and always exclude the people you would be paying to reach twice.
Check yourself
No score, no signup — pick an answer to see why it's right.
Question 1
Which signal holds up best as third-party tracking becomes more restricted?
Question 2
You build a lookalike audience. What is the best seed list?