Normally, when using a parameter to swap between measures, you're limited to using a single number format in a text table. But what happens when using the same number format makes no sense?
In our example, we're swapping between Total Cost (reported in $) and Visits (a count). We don't want to report Visits as a dollar-denominated amount, and we don't want Total Cost to be reported without a dollar symbol! So what can we do?