You will have heard of the ‘double opt-in’ and, if you have given it brief consideration, you will probably have dismissed it out of hand as it will restrict the size of your email marketing list. You might think that there can be no justification for this.

A double opt-in is when you require a subscriber to go through a second procedure before they are added to your email marketing list. It is obvious that the only outcome will be fewer subscribers so why do some companies use it?

Firstly, let me say that even as a supporter of double opt-in I would by no means suggest that it should be the norm. Indeed, my belief is that as a general rule it should be used for a small percentage of new subscribers to your email marketing list. However, it can be an extremely useful tool.

There has been considerable research, albeit mainly using low sample bases, which tends to show that there is little difference between the click-through rate of single and double opt-in subscribers. However, these conclusions are taken over a broad range and it is difficult to work out if they are dependable.

Further, it has to be accepted that not all subscribers are equal.

If subscribers have come via your website they will already have gone through a certain procedure before being included in your email marketing list, most notably actually clicking on a box to say they wish to subscribe as well as inputting their email address. This tends to show a certain commitment and knowledge. I would suggest double opt-in is not normally required in cases such as this.

Now let us take a campaign to obtain subscribers where there has been manual input of data. This would be, perhaps, at a trade fair, a counter or on the phone. You will have incentivised staff and received a considerable number of pieces of paper, or the data, and would be happy with all these new addresses for your email marketing list.

Ask yourself if you feel you could depend on them completely. There could be an error in writing the address, the person giving the email address might well have given an incorrect one or the person inputting might well have been after the promised bonus.

You do not want to be seen as a source of spam and you certainly do not want to be reported for sending unsolicited email marketing. So a second check can be beneficial.

Such addresses should be kept on a separate email marketing list initially and then a follow up email, essentially the double opt-in one, should be sent and the addresses not moved onto the proper email marketing list until the second, confirmatory email is received.

This email is unlikely to be classed as spam if no marketing is included and an explanation as to why it has been sent is clear. Staff collecting the addresses should be told to inform new subscribers to expect the second email.
One way of encouraging more accurate input from your staff is to refuse any reward for the address until the confirmatory double opt-in email is received.