Despite attempts to reinvent it, email is still one of the most popular ways to communicate across the internet. Developers have long been able to take advantage of Emails popularity using various libraries that support POP, SMTP and IMAP. This is fine when you have access to a publicly available web server, but for small and hobby developers this can be an unacceptable cost.
Email-list.com provides email marketing and social media tools for businesses. Recently the company announced an Email List API that gives visitors to your website access to counts and quotes on email lists.