The Feb. 2008 issue of Locus features their annual year in review, including a survey of the major SF/F magazines. For Analog Science Fiction and Fact, overall paid circulation fell 3.2% in 2007 to 27,399 (with subscriptions making up 22,972 of that number), while their sister publication Asimov's Science Fiction saw circulation drop 5.2% to 17,581 (of which 14,084 are sent to subscribers). The numbers for both these magazines are actually pretty good, with sell through on newstands increasing by a few percentage points and the steep drop in circulation seen in recent years leveling out.
Fantasy and Science Fiction saw a startling 11.2% drop in circulation to 16,489, almost all of that from their subscriptions. Realms of Fantasy saw a 2.5% drop in circulation for 2006--their last year for available numbers--to 22,544. The good news, though, is that RoF saw their subscription base grow by over a thousand. The other professional SF/F magazine, Interzone, saw its circulation remain in the two to three thousand range.
There are two interesting things about these numbers. First, newsstand sales remain a problem. New readers discover magazines by first reading them. If they can't find the magazine, they won't subscribe. The good news, though, is that all of these magazines except RoF are now available as electronic downloads from Fictionwise. As electronic reading devices become more accepted, I imagine this will offset the fewer and fewer newsstands which carry SF/F magazines. I'd also suggest Locus provide circulation numbers from places like Fictionwise in next year's overview.
Second, Fantasy and Science Fiction's circulation drop should stand as a testament to how data thieves can harm any business. According to editor and publisher Gordon Van Gelder, 2007 would have been a good year financially if not for the recent postage hike and the theft and abuse of F&SF's subscription list by "rogue subscription agencies, which cost us dearly." This appears to indicate that F&SF's large drop in subscribers last year was due to scammers contacting current F&SF subscribers. As an Asimov's subscriber, I have experienced these same scam artists, who call and try to con you into "renewing" your subscription. While I'd read announcements about these scams and hung up on them with a few choice words, it is understandable that many subscribers would fall for the scam, thereby alienating valuable SF/F readers and causing a deserving magazine to lose subscribers. I hope F&SF bounces back from this no-fault-of-their-own problem. I also encourage people to subscribe and support all these magazines.