FeedBurner - Why use it?

Gregor and Tatie, hi! Here, I have seen how Feed Burner e-mail subscription works. It's a nice mail icon on the right top of the page. If you use it, it redirects you to subscription page, where you put in your email, and than FeedBurner sends you a activation mail.

Tatie, for you it could be usefull, if you looke at: Millionaire Club Recommendations, at the right side of the blog, which send you to t what it looks like an affiliate programe of amazone. The guy actually recomends book for reading.

Still I don't understand it Blogger and FeedBurner feed can coexist?