Click on the EDIT button next to a subscriber in your list
You will now be able to enter all sorts of information about your subscriber such as Job, Date Of Birth, Address and much more. You can use this information later when sending campaigns to segment out subscribers. For example, you could say I would like to send a campaign to all Subscriber that live in Florida who joined my list within the last week.
Finally, click the SAVE button at the bottom of the page to save any changes.