As a media company we are constantly explaining to new clients what “opt in” really means and specifically what co-registration opt in is and why it is okay to mail to it. The word “opt in” itself has been the subject of intense debate among the online marketing world for quite a while, because there are various definitions of what is considered opt in. In the simplest definition opt in is the email address of a person who has opted in to a mailing list and has given permission for a company to email them.
Let’s start by examining what co-registration is; it is a method used to collect user information on people; usually this would be a separate check-box on a Web signup form where the user can opt-in to receive messages from a third-party and/or partners. The area of debate is can you as a company purchase a list of co-registration data if the users did not opt in to your site specifically? I say yes you can, so long as when they opted in that it stated that they would receive offers from partners and other sites that may have offers that benefit them. As long as this was made clear and they still opted in, then there is nothing wrong with purchasing and using this data.
One thing that you want to be really careful about however is make sure that you are purchasing from a legitimate company and that they are really selling you co registration data. Make sure they are a reputable company, make sure the data comes with opt in source, time and IP address so that you can prove that they opted in.
Another thing that you want to be sure of, if you are mailing this yourself be sure that you know what your hosts Terms of Service (TOS) and Acceptable Use Policy (AUP) are. It is likely that your host has a policy against this opt in or not, most hosts have a limited to how much email you can send out in one day or at one time. Sending mail at Constant Contact for example only allows mailing opt in that was specifically opted in to you, whereas Ad Mail allows co-registration data as long as you have the permission of the original list owner, but even Ad Mail is going to limit you to sending just a couple of hundred emails because as the list grows so do the problems, even in opt in lists. If you are planning on sending more than a few hundred emails it is recommended that you use a professional email marketing company.