Have any of your tried redeeming the "Virtual Getaways Certificates" (for $-off) through Global Impact?

Choose a multi-purpose travel certificate good for use toward travel-related services such as airline tickets, cruises, hotels and car rentals. A great option for the frequent traveler. Virtual certificate redeemable only through Global Impact, the industry leader in providing impeccable customer service. In order to make travel arrangements, please call Global Impact and provide the certificate number that will be displayed for you upon redemption of this award.

If so, have you been able to apply a certificate to the hotel stay of your choice?

UPDATE:
-I called Global Impact.
-They picked up the call within 1 minute.
-I was advised that...
-these certificates are not combinable
-GI books the reservation
-the receipt for the service (air/hotel/etc.) is submitted for reimbursement after service is consumed
-I called Thank You Rewards.
-On hold for 15 min -- then received cert #s.
-Called Global Impact back.
-Some challenges in booking (as the Starwood Luxury Collection Haciendas were not in their system), but we were able to complete the bookings.
-Apparently, I submit receipts on return, and will receive refunds within 14 days.

May not be the "best bang for the buck," but it is nice that you can use the points in this manner.