New subscribers are the lifeblood of an email program. Every email program will see some subscribers lose interest and either unsubscribe or stop opening emails. If you’re not replacing the subscribers that you lose, you’ll see diminishing results from your email campaigns. There are several methods for generating new subscribers, but how do you know what list building methods work best for your brand?

List building methods

In general, the best subscribers for the overall health of your email program will be generated from those frequenting your website. This audience knows your brand, your content, your products, etc… and decided that they would like more from you via email. 

There are a number of list building tactics you could try, including:

  • Placing a simple sign up form on your website
  • Offering a product discount for an email signup
  • Launching a lightbox on your site to collect emails
  • Placing content like guides or articles behind a signup form

Outside of your website, there are many other methods for generating new subscribers… although these are methods you will want to track very closely. With GDPR, CASL, and other email legislation being introduced, you will want to confirm any method you choose is compliant for any location you are sending into.

If you are a Twilio SendGrid customer, check that your acquisition methods comply with Twilio SendGrid’s Acceptable Use Policy and are unlikely to generate spam complaints from recipients. Outside of legal and compliance matters, it will be key to tag each source so you can monitor true results of these signups or easily address any issues that arise.

How to test your signup strategies

In our data-driven world, there’s no substitute for being able to easily test different strategies by their performance over time. When it comes to new address acquisition, testing a variety of tactics is made much easier if you can tag your subscribers by their source. If you are using Twilio SendGrid’s API, an easy and effective way to tag addresses by source is to utilize our unique arguments feature. Unique arguments are essentially tags that you can pass over to us with each message that allow you to do more granular tracking via the event API or the email activity page.

Metrics to watch

With each of these different strategies that you try, you will want to know which ones generate the most conversions or click throughs, which ones generate the fewest opens, and which ones generate the highest rate of spam complaints or bad addresses so that you can continually optimize for success. 

To summarize, some of the important metrics you will want to track will be:

  • Unique open rate
  • Hard bounce rate
  • Unsubscribe rate
  • Spam complaint rate

It will also be important to monitor these results over the course of months, not days. A signup source might show promising results out of the gate, but over the course of a month or two, those subscribers could lose interest or complain.

The value of signup sources

On the surface, a strategy such as co-registration might seem like an easy win. Co-registration is a method in which users are given the option (or forced) to agree to receive email from third-parties. For example, a user could be required to signup for marketing emails in order to open their free account. It may seem promising to get a large batch of new signups for a very low cost, but what’s the catch?

By tagging this source, you’re likely to see that subscribers mark your emails as spam at a much higher rate than normal, impacting your sends to engaged subscribers. By tagging and tracking the performance, you would then know to improve the signup experience so that it sets better expectations or does not use a method like co-registration. If results are very poor, having these addresses tagged by source will also allow for easy suppression from future sends. 

Tagging contact addresses gives you keen insight into what list building strategies are and are not working. 

Other methods, which on the surface might seem quite pricey per new subscriber, such as Facebook Ad Leads, could end up paying off in the long run. With a tactic like Facebook Ad Leads, you can get very sophisticated in your targeting and show sign up ads to followers of your brand or a competitor. Even though the cost per conversion is much higher, these subscribers are far more likely to engage with your content and complain at a much lower rate than cheaper methods. 

Find the best strategy for your brand

Exploring various methods for generating new subscribers can seem overwhelming at first, but with the proper tagging and the ability to monitor results, you will quickly find the methods that work best for your brand. If you need help from deliverability experts in optimizing your subscriber acquisition practices or just want to level up your email program, check out our expert services offerings. 



Denis O'Sullivan
Denis has been working in the email marketing space for 12 years. Most of that time was spent managing email programs for various brands. A native of Ireland, Denis spent most of his life in Florida before moving to Colorado. Denis enjoys exploring his new state with his family.