If you enter promo code BTN06 while signing up for BizPerks, the Northwest Airlines small business program, you’ll receive 50,000 bonus Biz Perks points.
These covert to, say, 5 free club passes and 5 free drink coupons or a domestic upgrade and a couple club passes.
The offer expires September 30th.
Update: To qualify for the points you need a flight in full fare coach (B fare) or higher by September 30th credited to the Bizperks account. Still worth signing up just in case, but no longer the gimme it first appeared.