Email Marketing

The relevant laws, some growth-hackery tips, and suggestions about good emails to send

This article is part of my Entreprenerd: Marketing for Programmers book, which is currently available to read for free online.

Even to this day, email marketing is underrated and underused by online marketers. This may be because we spend so much of our time online that we become desensitised to the content of promotional emails and overwhelmed by their frequency. Empathetically wishing to avoid burdening other people’s inboxes, we decide against equipping the businesses of our own creation with email campaigns.

But this is a mistake. Just because you hate receiving promotional email doesn’t mean that your customers feel the same way. In fact, promotional emails are welcomed by their recipients when they offer value—be that by announcing the availability of a much-anticipated product or offering a chunky discount for some doodad the customer already planned to buy.

Of course, like anything in life, haters are going to hate. In response to one of our company’s emailing campaigns, a disgruntled recipient emailed us to say, “STOP EMAILING ME ASSHOLES”. (For the record, I have never emailed anyone anywhere any assholes.) But, for every negative reaction like this, there were at least a hundred sales, completed quietly by smiling members of the silent majority.

Remember too that your subscribers can always opt-out of your campaigns by moving their mouse down to the “unsubscribe” button. Knowing this, you shouldn’t be too bashful about sending out emails. Marketing legend has it that the ideal frequency for promotional emails is surprisingly high: about one email per week. That’s probably about 50 times more emails per year than most of your competitors are sending.

Email marketing has a compelling commercial case. The initial infrastructure for sending them can be built without serious difficulty or expense, and the unit cost for each outbound email is practically nil. Once in place, these marketing systems can run with little or no maintenance for years on end, awarding your business a permanent and recurring boost in revenue. It’s like having a loyal door-to-door salesmen who works day and night to win you sales.

The strategic goals of email campaigns can be grouped into direct emails that unashamedly ask for conversions then and there and indirect ones that instead lean back and gradually fan up desire. Direct emails have discount codes and links to product pages, whereas indirect emails contain company news, useful tips (which conveniently portray the company well), drip-feed content courses, and notifications about goings-on over on the website. There is much debate about whether direct or indirect email campaigns are better, but little consensus has been reached.

The Law

The sending of promotional emails is regulated by a hodgepodge of region-specific laws such as the CAN-SPAM Act of 2003 (in the US) and Directive 2003/58/EC (in the EU). Generally speaking, full compliance with the main global rules requires that you:

  • Ensure that the subscriber opts in. Under EU rules, opt-in consent must be a “(1) freely given (2) specific, and (3) informed indication of the user’s wishes”.1 This implies that the ubiquitous practice of automatically subscribing registered users or past customers to mailing lists is illegal. Therefore, marketers who want to play it safe should ask their users to tick an explicit checkbox indicating their consent. Behind the scenes, the play-it-safe marketer should program their server to record the timestamp and IP address for when this ticking happened. This might seem like overkill until you realise that there have been court cases where companies had to provide concrete evidence that an opt-in event occurred. The most risk averse marketers go so far as to use double opt-ins, whereby potential subscribers must confirm their consent by clicking a link subsequently sent out in an email. Since access to email accounts is password protected, the double opt-in step is seen as strong evidence of genuine consent.

  • Provide a valid postal address.

  • Provide company information (e.g., registered company name and sales tax number).

  • Provide a (working) unsubscribe link within every promotional email.

Even though these requirements are, technically speaking, “the law”, it must be said that the overwhelming majority of web marketers ignore all but the need for an unsubscribe link.

Best Practices

  • Use images instead of just text for higher conversions rates, but always keep a textual fall back to cater to the substantial number of email users who disable images from displaying in their clients.2

  • Put a large button in the centre of your email even if it does nothing other than lead to your homepage. This practice is motivated purely by the observation that people love clicking on buttons. The text written on the giant button needn’t have any relation to its true purpose. For example, in one of our promotional emails we inserted a huge button that reads, “Activate Discount”. The reality is, though, that the discount had already been activated before the email was ever sent; we just wanted to give the email recipient a compelling reason to click the button and end up on our website again.

  • Dress this giant button up with URL tagging for better Analytics reporting. Ditto for any other links in your emails. Without this precaution, you’ll effectively be flying blind vis-à-vis your email performance.

  • Use 1x1 pixels (or third-party software) to track open rates and click-through rates.

  • Pay inordinate attention to your email subject line—unless it’s compelling, the email recipient will delete your email without inspecting its contents.

  • Be intelligent about who you email so as to avoid bombarding subscribers with irrelevant offers and jolting them to unsubscribe. To be clear, I am not advocating the need for anything remotely as sophisticated as artificial intelligence; in my view, it’s sufficient for your campaigns to implement a few simple rules of thumb, such as “people who buy the first book in our series will probably want to buy the other ones” or “people who bought our printer will probably want to order some ink later”.

Classic Promotional Emails


If your profit margins can take it, considering putting on frequent sales. At the very least, sales are a great excuse to remind your subscribers that you exist, and that it’s worth dropping by your website again.

Obviously, there’s no point in having a sale if no one knows about it. Email marketing comes to your assistance here by helping you spread the word to all your subscribers.

The limited time span of a sale compels leads into buying from you before they lose their chance for a discount. Therefore, be sure to prominently mention when your sale ends. You might even program your email to display the reduced “sales price” for whatever products the subscriber previously browsed.

Cart abandoners

Someone that added one of your products to their cart but didn’t finish purchasing it is a grade-A target for continued marketing attention. After all, you know that this person is—or at least was—interested.

Enter the cart abandoner’s promotional email. The point of this is twofold: to remind abandoners about the product they liked and to sweeten the deal just enough to persuade them to buy (e.g., by offering a discount). Just as with the sale email, there’s no harm in applying a little time pressure too (e.g., “this weekend only”).

The trick with discounts in cart abandoner emails is to minimise cannibalising the margins you would have earned had you been able to sell that item at full price. You want to avoid sending discounts to people who would have bought the item in the cart at full price a few days later. One tactic for doing this is to study your historical shopping cart data and figure out the behavioural patterns of your previous cart abandoners. For example, I found in my business that there was a 95% chance that someone would never complete an order 9 days after they abandoned. Based on this data, I programmed my cart abandoners email to only send out a discount 9 days after the cart was abandoned.

Within the email, I present the discount as a store-wide “sale” so as to encourage the customer to buy more that just the original abandoned product, and so as to stop them figuring out that if they leave products sitting in their cart, they will automatically get a discount a few days later.

Recent churners

If your business model is based on monthly subscriptions, you’ll know that a certain percentage of your customers end their subscriptions every month. These are good candidates for future marketing emails which remind them to get started again.

  1. Directive 2002/58/EC 


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