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.
Sample review: Optinmonster “has various forms you can embed on your site to help with email conversion but one of the most interesting ones is the popup. You can set the popup only to appear on ‘exit intent’. This means that your website visitor can browse all they want and when they are about to exit the website you can have a popup appearing tempting the visitor to leave their email address.” — RazorSocial (World)