title: Tableau formula Help (new user v repeat user etc)
body: <p>Hi I am trying to figure out how to write the proper calculation.</p>
  
  <p>My objective is to determine news versus repeat users by month using an email address as the identifier.</p>
  
  <p>If an email address occurs once they would be counted one time as a new customer. If their email address occurs a second time and a third or fourth etc, I would want them to be counted as a repeat customer one time only for each month they purchased.</p>
  
  <p>Thanks</p>