The automatic feed registering is used to automatically register the posts on a blog as they get published. To use it you have to associate the feed with a previously created profile.
To access the functionality you have to go to "My account" / Registration feeds. Once there you can enlist the direction introducing the RSS feed, blog address, selecting the content type, the registration profile, etc.
On your blog, preferably in a area of the page to which access may be permanent, you have to publish one of the verification codes Safe Creative creates so that our bot will be able verify that the blog is yours.
You can also register file feeds, image feeds such as Flickr, Zooomr, or podcasts introducing the the specific feed for those contents.