This document provides 21 ways to grow an email list fast. Some key techniques include putting a sign-up pitch on all stationery and business cards, including a sign-up link in every blog post and social media profile, offering a free webinar or podcast series to attract subscribers, using visual elements and specific landing pages optimized for sign-ups, and seeking out interview opportunities on other podcasts and shows. The overall recommendations are to test multiple list-building tactics that appeal to your target audience and combine compelling incentives with easy sign-up processes.