Create as many subscription widgets as needed and test their performance across your sites. The subscription widget’s intuitive drag-and-drop editor allows customize your forms with a few clicks of the mouse. Edit the layout, text, image, and color scheme order to fit your brand’s visual aesthetic. When you’ve landed on a design you’d like to use, the tool will generate an HTML code to be copy and pasted into your website’s source code.

These are simple formula for growing a massive email list. The 14 list building hacks to grow an email database super-fast are in no hesitation effective if done correctly. Not all marketers try to think outside of the box to stimulate growth, but pretty sure whenever they read this article, they could learn here and would use it to experiment with the new ideas, coming up with creative ways to build a business.
It’s extremely affordable (starting at $15/month), while incredibly powerful and easy to use. I also find that GetResponse have some of the best newsletter template designs around. Aweber is another good call, but I find their user interface a bit outdated and clunky (plus, their pricing starts at $19/month – not a big deal, but considering they’re not quite as good as GetResponse IMO this pushes the needle in favour of GetResponse even more).
For effective and actionable results, you should do A/B tests, which test two (or more) different approaches. For example, you could send half of your list one subject line, and an alternate subject line to the other half. You could also A/B test the two approaches with a small subset of your list, then send the winning headline to the rest of the list.