Audience layering means adding extra targeting to your campaign based on who the people are, not just what they searched. Without it, your ads show to anyone who types in your keyword, including people who are unlikely to buy. For example, a keyword like "running shoes" could attract casual browsers, kids, or people looking for free options. Adding audience layers like age range, income level, or past website visitors helps you spend your budget on people who are more likely to convert. Running ads without any audience layering usually wastes money fast. Do you use audience layering in your current campaigns?