John Scalzi considers the market numbers on who's buying fantasy and science fiction:

"I have a friend with access to BookScan, which tracks book sales through stores and retail outlets, who at my request checked the aggregate bestseller list sales of adult fantasy and science fiction against the sale of YA fantasy and SF. Without mentioning specific numbers or titles, my friend says that last week, the top 50 YA SF/F bestsellers outsold the top 100 adult SF/F bestsellers (adult SF and F are separate lists) by two to one. So 50 YA titles are selling twice as much as 100 adult SF/F titles. The bestselling YA fantasy book last week (not a Harry Potter book) outsold the bestselling adult fantasy book by nearly four to one; the bestselling YA science fiction title sold three copies for every two copies of the chart-topping adult SF title."

Our own Nielsen BookScan tipsters filled in the info on those titles. The images above are not uniformly to scale—Jim Butcher's Small Favors sold about 4,700 reported copies during the week in question, which is clearly dwarfed by the 22,700 or so for Erin Hunter's Outcast, but it still actually outsold Scott Westerfeld's Uglies by twice as many copies, which in turn outsold the classic Orson Scott Card novel Ender's Game by, as Scalzi says, 3-to-2. (And that raises an interesting question: Why are the bestselling science fiction books for both YA and adult readers older works? One could also point out that the primary audience for Ender's Game in the 23 years since its publication has shifted towards the adolescent market, but that would just be twisting the knife.)

"As a final kick in the teeth," Scalzi observers, "YA SF/F is amply represented at top of the general bestselling charts of YA book sales, whereas adult SF/F struggles to get onto the general bestselling adult fiction charts at all." The overall effect? Adult readers, he proposes, "are missing a genuine literary revolution in their genre because the YA section is a blank spot on the map to them, if not to everyone else."

We just like to revel in the fact that the bestselling fantasy book in the country last week was about cats.