I for one, started to suspect the carpet as soon as we got the flashback to when the protagonist's childhood friend disappeared. The friend who it is mentioned, liked to sleep between a bunch of these carpets. So either i'm deranged, and just lucky that "The carpet did it!" was right, or there was some foreshadowing.
I give it points for a creative solution to the mystery, but i do agree with some posters that the solution felt a little contrived-- at least it wasn't a very satisfying solution. Perhaps if the author made me really feel the horror or weirdness of the carno-carpet that would have helped.
I also totally missed how protagonist came to the conclusion that the carpets were sentient and could communicate with each other. That didn't seem necessary for an organism to occasionally eat something.
This was apparently supposed to be a hard-boiled, film-noir detective story. So far so good, Mystery & Sci-fi is a great combination, and i'm always happy to see more of that. However i felt like the narrator worked too hard to remind the reader that this was a gritty, dog-eat-dog world. "Telling" when there was already enough "Showing," as if she was afraid we wouldn't notice that this was a hard-boiled world. I know those sort of asides are part of the genera, but it didn't ring true for this narrator. That's the sort of thing that a person who lives their whole life in one place tends not to notice, but take for granted.
Final rating:
-- Leave in iTunes to listen to again sometime.