Hey, take Monday off and you will need hotel points to overnight in SJU (there are worse things in DEC than waking up in San Juan right)? I think this is a at least one for Washington folks! Here are the numbers:
8,102 MQMs at 5.2 CPM
Bookable on Delta.com
DM yields a very nice 18,230 Skymiles per CWSI.net!
EDIT: Looks like SFO-SJU on weekdays can push this SUB $400 for a great FlexPerks ticket!