You don't even need a Kobo device to get the discounts in the Kobo store.
I actually have many more paid purchases from Kobo than Amazon because of the coupons, which I originally got by signing up for the newsletter, and now keep track of via the
KoboBooks.com Discount Codes thread in the Kobo forum, which is very handy as everyone contributes their finds and someone keeps the first post up to date with latest valid coupons.
ETA: You probably can't use Kobo coupons in the Comixology store, if that was what you were asking, but the equivalent comics titles seem to be discountable in the Kobo versions.