Founder of MailboxMetrics.com, a free email marketing grader to help improve your Mailchimp campaigns. Particular strength with SaaS and eCommerce startups.
Email is one of the highest ROI marketing channels... IF ... you have a clean, segmented and engaged list. I will help you to increase your revenue in your SaaS or eCommerce business using Mailchimp, using a clear and effective approach.
For general Win Back emails, An Ometria report from their customer base displays an average conversion rate of 1-3%. Haven't got too much insights into the subscription based products though.