The Marketing+ menu includes important features that allow you to use more advanced filters when segmenting subscribers, automatically send messages when certain events occur (e.g. someone's birthday), create forms that can be used to update subscriber information, and store up to 39 different pieces of information in your subscriber database (39 customizable fields).
Create customized, hosted forms to ask your customers to update their profile. For example, ask your recipients to add their birthday to their profile in order to receive a special offer on that day.
Automatically send email series (Workflows) or single messages (Tasks) based on when a certain event occurs. For example, send a special discount to a customer on their birthday, or a coupon 30 days after the latest purchase.
Sometimes there can be a bit of confusion when it comes to using groups, filters, and triggered messages (automated messages). Here is a hands-on overview that might help further clarify things: