Each section represents a footer column and not using a column will expand the other columns.  The content field for a section will display in its respective column. 

Content > Link Lists > Social Links

The monklet "Social Media Monklet" is used in "footer column 2" and displays icon links from a link list. Each link will need a URL and and Icon Class.  The custom icons are created by entering a custom class in the "icon class" field (ie: icon-twitter). 

The monklet "Newsletter Sign Up" is used in "footer column 2" and displays an email sign up form, which will add subscribers to the "Newsletter" group (People > Groups). 

If this monklet is deleted from the footer column 2 section, then this sign up field will be removed from the footer.