I just figured I would pass this plugin and tip along. I worked on a project for a client last week who wanted to start a newsletter for her business and needed some help. I helped her set up a branded email newsletter template on Mailchimp and a sign up for my newsletter form on her website. She also asked me to place the form at the end of every single blog post on her website. I have never been asked to do that before but I know it is possible. After a bit of research and trying out a few WordPress plugins I found Popupally. Although it has options to add your opt-in as a pop-up (which I think is annoying), there is another option that adds it to the end of every blog post. Problem resolved! I think it looks great on her website and I liked it so much I added it to my own. Check out how it looks on Artful Kitchens. If you are using your blog on a regular basis and are getting traffic to your website I think it is a great way to grab those emails of people that are interested in your services.
If you need help getting Popupally installed on your website, please feel free to contact me. They have a free or paid version but so far I think the free version of this plugin does the trick.