Email marketing delivers ~$36 ROI per $1 spent. Your list is an asset you own. Build it with a specific, valuable lead magnet. Place opt-in forms within blog content, on your homepage, as exit-intent popups, and on dedicated landing pages. Send a strong welcome sequence. Send at least weekly. Segment by behavior and interests. Remove unengaged subscribers every 3–6 months to protect deliverability. A smaller, highly engaged list dramatically outperforms a large disengaged one.