1. Click on the Promote tab
2. Select the campaign you want to tag and check the box next to the campaign name
3. Click the Add To Tag button and name the tag
4. Click on the Fans tab
5. Select Downloaders Of Tag in the Smart Groups section on the left
6. Select the tag you created in Step 3
7. The default display is 'For the Last 30 Days', so just select 'All Data' from that drop-down