Wider reach but less costly. So long as you have built a robust mailing list, email marketing software allows for reaching to a targeted market at a significantly lower costs than traditional outlets like tv, print and radio. Moreover, the audience is more targeted granting you built the list using opt-ins or follow a permission marketing strategy. Some companies start with a purchased list to get initial subscribers, but it is still best to build the list around your customers. As you expand the list with incentives like white papers and deals, the cost per email drastically drops, further increasing the ROI of email marketing software.

Slack is a powerful messaging app that allows you and your teammates to quickly message back and forth without the hassle of email. But it's not just AOL instant messenger 2.0. Slack has powerful features and integrations that make it possible for you to integrate all of your other daily tools -- like Trello, Gmail, Giphy, and so many more -- right where you're already communicating. You can start channels between different teams or just chat with specific colleagues. Slack makes remote and in-person work possible and easier than ever.
MessageGears is a hybrid email marketing system that combines the security of an on-premises system with the scalability of the cloud. The service connects directly to any local or remote database, data warehouse, e-commerce system, or content management system. There is no need to extract, transform, or load customer data into the system or to move or replicate data. Features include subject line previews and testing, spam testing, and automation, drip and trigger campaigns.

Ayisha, my understanding is that Wysija will sort of do this for you. If I have it right, you can create your 30 messages, but you can’t group them into a series where there’s the first, second, third. My guess (I haven’t played with this yet, but plan to for a shorter series) is that you’d have to set each one to go out a certain number of days after signup. It’d be a real pain, but it would work.
Rather than relying on a series of commands listed one after another, GetResponse utilizes a more engaged and visual approach: Users drag and drop actions into the workflow, directly linking triggers and commands in a way that feels more like completing a connect-the-dots than setting up automated emails. This simplifies what can be an otherwise complex process and makes for one element of the GetResponse user experience that beats out MailChimp in terms of convenience.
This article is informative, but it does not offer distinguishing features between the services covered (other than mailchimp is free). You seemed to go to great lengths to say good things about each – although I’m sure each services has positive aspects. I would have benefited much more from a rating of some sort of the various features of each service, or at least the pros & cons of each.