Advertising Doodle features Engineering

Doodle switches to HTML

We send hundreds of thousands of notifications per day that are related to the administration of Doodle polls. Some of you may have already seen that we’ve switched to HTML e-mail notifications. This was an important step to improve the overall user experience of one of Doodle’s core communication streams. We handle these messages in-house so that we can have full control over what our users get. You’ll notice that the HTML e-mails look better and offer more helpful information in one look.


The basic approach to develop the new e-mails involved iterative steps and a lot of testing. Over the course of a month, we released six layout versions to small subsets of users and measured KPIs like the opening rate and the click-through rate. Many users and a service called Litmus helped us test the designs in a variety of e-mail clients. We immediately incorporated the feedback and were able to measure the improvements instantly.

Initial text-only notifications
First iteration
Five iterations later: today’s notification


As a result, you can now experience HTML notifications in a fresh and structured layout that gets displayed in all modern e-mail clients. Poll initiators are much less likely to send out the admin link that is not intended for the participants. They can also invite participants by clicking on the invite buttons in the HTML e-mail. The final layout has been selected because it achieves an optimum click-through rate on links to Doodle polls, other Doodle content and advertising partners. Just like before, you can get rid of all advertising on Doodle by choosing a premium subscription.


  • a text-only fall back increases the click through rate significantly
  • over 50% of all Doodle notifications get opened
  • less clicks on advertising was equivalent with a higher lead rate, which is good for the advertiser as for the Doodle user

In the end, it was trickier to develop a good HTML e-mail than a website because there are even more e-mail clients than there are Web browsers. That was one of the lessons that we learned that anyone who’s created HTML e-mails before has also learned. Here are some helpful resources that we used:

0 comments on “Doodle switches to HTML

Leave a Reply