Can't get the whole crew to throw down for tickets at the same time? No problem! GA by section allows you to sit wherever you wish in that respective section.
For example: If you purchase a GA 100 section ticket, you are free to roam about as you please in the 100 section. Your GA by section ticket allows you to choose where you sit in that section only. It does not allow you to sit in other sections. Make sure you coordinate with your crew on which section you're purchasing for!