This is just a basic campaign structure that highlights how mboxes and offers come together.
As you can see the one constant is the mboxes themselves. Every Experience that is part of your Test or Campaign design will have the same mboxes. In this example we have two mboxes working together for a particular Experience and there is no limit to the number of mboxes that can be used in an Experience. Using more then one mbox for a Campaign is a very popular approach among users of T&T as it allows you to run your optimizations across different pages and mediums such as email and display.