Spreading out submissions over a period of time means choosing to control the rate at which submissions are made to directories. Submissions can be made all at once or can be 'staggered' or 'spread out' over a period of 2-5 weeks.  This feature was created to address the fears of those customers that expressed concern about getting penalized if links to a website were to appear all of a sudden. However since links are not instant, and could take anywhere from 3-90 days to appear, there should be no reason to worry. Even so, the option to 'stagger' or 'spread out' submissions over a period of time remains for those who would like to further delay the rate at which their links appear.