I recently viewed the @coinbase onboarding process and noticed a very nice “invite friends” link easily and readily viewable in the top nav. This is a great idea and one I think a lot of sites are not doing but should!
One additional thing would be to add video and provide ideas of how you could share with friends. #coinbase provides the gmail, share, tweet buttons but they also need to help people with ideas of how to share. Providing some videos of ideas or a articles/ebook would be great! Also adding text messaging would be critical, it’s the fastest way to hear and be heard!