Some companies are going beyond the eBook, offering services, games, even physical books in exchange for your email. Here's a quick list of companies using unique opt-in forms.
I haven't seen this written about a lot and I would love to build this out with your contributions and examples. Have you seen anything interesting out there? Is your company doing something different? Do you see the a difference in conversion rates?
Join over 70,000 growth pros from companies like Uber, Pinterest & Twitter