Cross listings are helpful marketing tools in VBO that allow future events to get more exposure and, potentially, more traffic. Future events that you assign to an upcoming event will be presented to the customer during the online purchase process. 

Note: There is also a global cross listing option. On the 'Open Events' page, use the checkboxes next to the 'Select Action' drop-down menu to display an event on all open events you have available for sale. If you have a cross listing set up on a specific event already, those events that you have assigned will be the default.

You can only have ONE cross-listing message that is global for all events.  

Additional Info -