If you buy through greenpoints.com and giftcertificates.com, you can get the certs immediately (or nearly so) and get greenpoints with a value of about 8% of what you spend (assuming you convert greenpoints to frequent flyer miles on either American Airlines or Delta). That's the best I can do, if I'm not willing to wait. The 10% discount on volumebuy isn't worth waiting for a whole month.
Remember the good old days when you could get 25% off at volumebuy? I wish that I had bought much more than I did -- and I bought a lot!
Bruce