rickyffff,
This is a great question. There is no OOTB way to do this currently. However I can imagine that you might be able to accomplish this by doing the following:
1. Create some custom code that keeps track of how many times the mbox was viewed by the visitor.
2. Store this number value in as an mbox parameter.
3. Build a custom audience based on that custom mbox parameter.
4. Add the audience as an additional Audience Targeting rule to the mbox in the conversion metric. See screen-shot below.
Keep in mind this will also make it so that the conversion will only increment after the mbox is viewed N times.
Hope this helps!
Viewed mbox N times:

Mihnea Docea | Technical Support Rep, Customer Care | Customer & Employee Experience | Adobe | (:: 1 (800) 497-0335

