If you're looking to grow your mailing list (and you should be, as email marketing is alive and well) then you need a solid lead magnet. What kind depends on your business and your industry.
If you're in SAAS, a white paper is probably your best bet. If you're a solopreneur, a guide or checklist works great! Other businesses do well with webinars, ebooks, or mini-courses. If you're not sure what lead magnet your business needs, let's hop on the phone and I'll help you decide.
Webinars, eBooks, & Mini-Courses
Clients who have hired me to help with these types of lead magnets have typically requested I not showcase them publicly on my website, but I'd be happy to directly send you samples. You can do that here.