To expand, that means that if a user's average lifetime clicks is .5, an email sign up is worth $50 in eventual revenue. I have worked with clients (retailers)

To expand, that means that if a user's average lifetime clicks is .5, an email sign up is worth $50 in eventual revenue. I have worked with clients (retailers) on their numbers and found that a subscription (pen, paper and a person asking a couple of questions) is worth more than a sale.