Returning visitors are already familiar with the offer/brand, so there's less friction because they've seen your promotions, maybe trust the site a little, and often are further down the decision path. First‑time visitors often need more convincing: you need good landing pages, social proof, strong calls to action. In affiliate traffic especially, when someone returns via retargeting, email follow‑ups, etc., those touchpoints help warm them up, increasing conversion odds.