Some bloggers prefer people to subscribe by email, because this gives them access to the list of email addresses of their subscribers - making it possible for them to send messages to subscribers separately from posting to the blog.
Getting a list of subscribers-by-email is easy, but you do need to have software that can open a Comma Separated Values (CSV) file to see the list - Microsoft Excel is a tool that lots of people use, but there are many others.
Warning:
I have not investigated if there are any Feedburner Terms and Conditions about what you may or may not do with the list of subscribers. I expect that there are some - it's up to you to make sure that anything you do with the extracted list meets these rules.
How to see your list of email subscribers
Log in to Feedburner, using the Google account that owns the feed.Click on the name of the feed you are interested in: this opens the Feed Stats Dashboard in the Analyse tab.
Click on Subscribers from the menu on the left
Scroll down to the Email Subscription Services area
Click on Feedburner Email Subscriptions
Click on Manage your Email Subscriber List
Click on Export - CSV
The download starts: depending on how your machine is set up you will probably be asked what you want to do with the file (mine opens it in Excel)