There’s been debate about single vs. double opt-in for a long time.  Here’s a quick review of some of it – something to keep in mind when you’re adding people to your list.  And why you might care.  Summary: because not-caring might cost a LOT of money.

First, let’s be clear on the question.  When someone is entering your list (newsletter sign-up, for instance), some places want you to fill in your email address and click an “add me” option – and that’s it, you’re in.  That’s “single opt-in”.

Others want you to then click a link in an email they send you after you clicked that button.  That’s “double opt-in” … essentially you’re confirming that it was you who signed up (not someone else with your address).

So which should you use?

There are a few reasons people ask for email confirmation, and a reason why some people don’t.

Firstly – why?  It filters out low-value entries – bots, some spammers, pranksters and people who really weren’t interested (if they can’t be bothered clicking a link, will they read your content or buy your services?).

So why doesn’t everyone use double opt-in?  It also filters out some legitimate sign-ups.  Every extra step is a chance for someone to not follow-through.  Maybe the mail got eaten, maybe they got distracted, maybe they didn’t understand.  Using double-opt in will slow list building.

So, from a marketing point of view, it’s quantity vs. quality, and that’s where the debate’s been for probably 10 years or more.  If you google the topic, this is the general gist.  Articles like this explain the marketing side.


Lately I’ve been wondering if that’s the only or best viewpoint.  There’s also a legal one.


Now, first of all – I’m not a lawyer, so take this with a grain of salt.  Probably three.  Get your own decent legal advice rather than relying on me – all the usual disclaimers.

Anti-Spam legislation is something that I don’t normally see mentioned in these articles.  Perhaps because many of them are written by Americans for Americans – and the US’s law isn’t the strongest out there.

Some countries have a pretty relaxed approach to spam … you can email anyone anytime, until they ask you to stop.  Effectively, a “maybe means yes” approach.  For these countries, a single opt-in is probably fine, as long as you include an opt-out option.

But other countries aren’t like that.  Some of them say “no marketing emails unless the person explicitly asked for them”.  In those countries, it’s a “maybe means no” approach.

Explicitly asked for it usually means that.  Not “they bought my product last year”, or “I know they’d like it”.  They have to actually ask for it.

The penalties can be expensive.  In Canada, you might get away with a warning.  But you can be fined up to $1million, and $10million for your company.  Some parts of Europe risk a jail sentence.

Just to make it even more fun, countries usually say that if the recipient is in their country, then their law applies.  Even if you didn’t know they lived there.  Safest assumption is probably to comply with the most restrictive law that you think you might be dealing with.  Which gets fun when you’re talking international lists and people not necessarily telling you where they live.


I lean towards double-opt-in (email confirmation).


A final bit of icing: your email provider\auto-responder often also has a stake in it.  If you get their servers blacklisted due to spam complaints then their other customers go out of business.  Infusionsoft, for example, has some pretty strict rules in this area.  Check out their email compliance guide if you’re not clear on it.