I was thinking the same thing, perhaps it's British based thing as the Zing stores here sometimes carry comic trades from Marvel and DC but I've never seen Dark Horse, Image or IDW stuff there.
It would seem strange for them to get exclusives out from a smaller publisher out of the blue without any fanfare or media releases.
I'll keep an eye out and let you know if I spot them but perhaps an email to IDW to clarify what and where these zing exclusives are actually from.
Looking For: Wreckers Saga TPB Collection (with Requiem)