1. Content Upgrades: Offer valuable content such as eBooks, whitepapers, or exclusive articles in exchange for email addresses. 2. Social Media Promotions: Utilize your social media platforms to promote your newsletter or email list. 3. Website Pop-ups: Implement exit-intent pop-ups on your website to capture visitors before they leave. 4. Partnerships: Collaborate with other brands to cross-promote each other's email lists.