For monthly marketing / newsletter emails that go to a list, one way to see what’s working and not is to see what’s opened and what’s clicked. However lately I’ve seen marketing emails that are getting readers to rate the quality of the content. Embedded at the bottom, readers get a 3 or 5 point scale to say if they enjoyed that issue. I’d love to have a tool that we can implement on emails through HubSpot as another measure of content quality, and who gets as far as the end of a newsletter.
Two examples here

