Emma has tons of email templates to choose from, as well as drag-and-drop editor for custom designs. This is their main value proposition (superior design qualities). You can integrate this software with lots of other programs such as Google Analytics, Aviary and several social media sites. Reporting features are very easy to use and give a good overview of results.
Not only is InVision's newsletter a great mix of content, but I also love the nice balance between images and text, making it really easy to read and mobile-friendly -- which is especially important, because its newsletters are so long. (Below is just an excerpt, but you can read through the full email here.) We like the clever copy on the call-to-action (CTA) buttons, too.
A tracking pixel is a snippet of code that allows you to track your subscribers’ activity across various channels like your website, landing pages, and newsletters. Then, you also have the option to send emails triggered by certain behaviors. So for example, if a subscriber goes to your site and checks out your product page, a tracking pixel can send an email with a special offer for the specific product the viewed.