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How Personalized Emails Work
How Personalized Emails Work

Understanding the technicalities behind the Personalized Emails

Dan Macarie avatar
Written by Dan Macarie
Updated over a week ago

This article introduces you the technical aspects how Nosto Personalized Emails work.


Technically a product displayed in Nosto Personalized Emails is a combination of two images which are loaded from Nosto to a newsletter or other email where applied. One of the images features the product thumbnail while the other product details such as name, price and other selected information.

This effectively means that content will change dynamically and automatically every time a widget is loaded as a part of an email. For instance, if a product is available when an email is created and sent, but sold out or removed by the time a recipient opens up an email featuring Nosto Personalized Emails, a sold-out product won’t appear on an email and is replaced with other product.

Supported Platforms

Nosto’s Personalized Emails module supports any modern email engine or cart solution. Configuration and exporting the email widget from Nosto doesn’t differ between different email engines making the process very simple and straight-forward for all users.

Currently we support hundreds of different email engines out of the box and more are continuously added, but if your service isn’t available on the list while creating a widget, you need to insert the email variable manually while creating one.

Email variable is a variable which outputs recipient’s email address in your email engine. The variable is used by your email engine itself so it’s documented and available in your email engine’s technical documentation or through their support.

Adding Widget To Emails

Adding widget to an email engine is covered thoroughly in getting started guides. In short, a code snippet which is the widget itself is exported from the Nosto admin and then imported to an email engine as a part of the email template itself.

Applicable Email Types

Email widget can be included to any email type sent to customers, but here’s a couple of examples where you might want to try the widget for inspiration:

  • Newsletters and similar recurring emails

  • Registration completed and similar welcome-emails

  • Order confirmation notifications

  • Order shipped notifications

  • Greeting messages

  • Review product emails

Identified Recipients

A recipient can only be treated with a personalized recommendation in the Personalized Email widget if Nosto is able to identify a recipient by an email.

In practice this means that personalized and individual content can be served only to those recipients / customers who have either logged-in to the store, given their email address through Nosto’s pop-up or purchased something during the time when Nosto has been collecting data from the site. Uploading email address database which most likely is more extensive than Nosto’s is not supported as Nosto can’t merge browsing and shopping history of these clients to their email addresses. In other words, Nosto needs to associate an email address to a user first by monitoring their behaviour on the site.

The number of identified users will grow by time, but to tackle the deficiency, an automatic fail-over mechanism is implemented to all Personalized email widgets.


A fallback mechanism is applied automatically when a recipient of an email can’t be served with personalized content. By default, the fail-over mechanism is always overall most viewed products of the last week. In practice, if Nosto doesn’t have browsing history for an individual recipient, an overall top list is displayed in the email instead.

Name the Personalized Email widget title accordingly as all recipients or customers can’t be served with personalized content from Nosto. Title such as “You might like” suits both use-cases, so it’s better than possibly confusing “Your Browsing History”.

Widget Design

Widget design is customizable and covered in detail here.

Campaign Types

Best Sellers Recommendations

A Best Sellers recommendation type is similar to on-site recommendation Best Sellers and Trending Products and will display most viewed products of the last week or from a specific category. It is a generic recommendation hence all other recommendation types fall-back to a toplist, in case they’re not applicable.

Top list is a great tool to promote currently “hot” products and inspire customers to return shopping.

Personalized Recommendations

Personalized recommendation is exactly the same type to an on-site recommendation with the same name.

Recommendation displays products a recipient viewed or added to their cart, but did not buy, during previous visits to the store, giving more weight for items viewed more frequently or held in cart also excluding bought items. It’s effectively a weighted and smart browsing history and a great tool to remind about previous considerations.

Browsing History

Displays visitor’s browsing history in an linear order. Similar to personalized recommendation, but it doesn’t add any weight for view time or order. In other words, products are displayed in the order they have been browsed, in practice max. four most recently viewed products.

A great tool to remind about previous considerations if you send newsletters daily or weekly. For monthly newsletters personalized recommendation might work better, but ultimately the choice is yours!

Displays new products related to a visitor’s entire browsing history, excluding products a visitor has already browsed, by comparing visitor’s browsing history to similar profiles. It’s a great tool to introduce something new that fits customer’s preferences, especially after a customer has purchased something as it suggest something that goes well together with previously considered and bought items.

Product based cross-selling

Displays product recommendations that are related to a given product, such as “Customers Who Viewed This Also Viewed.” To relate to a product, use the field "Product ID" beneath the preview. This helps you understand which products will be recommended using the Preview function. 

If you're satisfied with the results, input the same Product ID on the Snippet configuration step:

See PRODUCT ID input field on top on the HTML Placeholder

Cross-selling and up-selling has include and exclude rules allowing filtering which type of products are displayed in a recommendation, for example controlling whether the recommendation displays alternatives or supplementary products. The recommendation is also controlled with scoring settings adjusting how relevancy between recommended products is assessed.

Order Related Recommendations

Displays product recommendations that are related to the recipient last order on the store.

Live Preview 

When you select a campaign type, you can preview the recommendations via the live preview function under Visual Settings:

You can also visualise via the mobile tab and adjust the behavior on mobile under the product images settings.

If you wish to previsualize how the email widget behaves when displayed to a given recipient, you can input an email address and preview as an existing user:

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