Bayer Animal Healthcare is issuing $20 vet certificates for preventative care. (e.g. vaccinations, wellness exams, flea, tick, heartworm preventitive etc.)
The coupons are being issued online until 9:00 ET tonight at http://www.gettothevet.com/
They issue coupons on the hour every hour until a total of 80 each hour and 1000 a day are given. Good luck getting one. I did!