Review my startup: Pepnest-plain text alternative to Mailchimp, Aweber etc

We just launched a mvp here http://pepnest.com and really need your feedback on the idea. We are creating a plain-text and simple email marketing product. We are banking on couple of assumptions as follow 1. plain text emails have better response rate 2. non negligible no. of people who would like to send plain text emails 3. 50% of emails are read over mobile and plain text emails suits mobiles the most 4. there is a room for a cheaper option with limited features targeted for specific cases

Do share you feedback.