Keywords Are Your Target
You're selling custom t-shirts for student clubs. Which keyword should you bid on?
Option A: 't-shirts' (searched 500,000 times/month)
Option B: 'custom club t-shirts for schools' (searched 200 times/month)
Option A gets massive traffic but nobody wants what you offer. Option B gets tiny traffic but every click is gold. Good keyword selection is about precision, not volume.