The document discusses different targeting strategies for online advertising including segmenting audiences based on demographics and interests, targeting based on behavioral data like search terms and browsing history, and testing targeted content to optimize engagement and conversion rates. Specific examples show targeting Spanish language users in Google searches increased click-through rate, conversion rate, and revenue per visitor. Targeting content to affinity groups like musicians also increased engagement and revenue. Targeting search results and pages based on intent was shown to significantly increase conversion rates and revenue per visitor.