I got an email today offering a special two-for-one "combo" subscription deal for Asimov's Science Fiction and Analog Science Fiction and Fact. It's an annual subscription deal -- at $29.90 (US) per year for
both magazines, plus the 12 most recent back issues from each (24 total).
If you previously subscribed to the two-for-one monthly deal, there are instructions on how to upgrade to the annual subscription. I upgraded without any (apparent) problems.
Combo deal at Barnes & Noble
I didn't see any restrictions, but I can't say for sure it will work for everyone. Good luck!