Why aren't they as effective? Contextual ads is what made Google big in the first place, and intuitively it makes sense why they would be the best. It's really

Why aren't they as effective? Contextual ads is what made Google big in the first place, and intuitively it makes sense why they would be the best. It's really weird that personalized ads work well! Makes no sense. Everyone hates how they get ads for stuff they already just bought and so on.