This is an Email marketing software. It helps business owners to reduce the cost of sending newsletters by up to 85%.  It sends emails to up to 100,000 subscribers per day at the rate of $1 per 10,000 emails. This will cost you hundreds of Dollars on a monthly basis if you use email marketing platforms like Mailchimp. 

You can also build unlimited email list by just connecting this software to your website through the API.