I a have a free image hosting website: www.heyimage.com I advertise on google adwords, and getting like 6 - 10 members to join my website everyday, but it seems these members are not very active. Mostly they even do not add any photos to my website. So I thought maybe I will prepare 5-6 follow up emails, and email my new members, with 2-3 days pause, and introduce them www.heyimage.com features, maybe after that they will start using my website more? Or they will just mark as spam my emails?