Glossary
Targeting
Choosing who sees the ad: GEO, city, language, device, OS, browser, carrier, hour, interests, age, placement. Every source has its own targeting; the tighter it matches the offer, the less traffic is wasted.
Targeting starts with what the offer requires (GEO, device, sometimes carrier) and narrows to what converts: hours of the day, OS versions, placements, subscriber age on push, interests and lookalikes on social.
Over-targeting is its own mistake: too narrow an audience makes the platform charge more and burn the creative faster. Start with the offer's rules, cut what loses money, and let the data narrow the rest.
Related terms: GEO, Qualified visitor, Blacklist, Whitelist, Retargeting.