According to the Kobo Facebook page...
Get 30% off this Bank Holiday long weekend! Those are savings you can take to the bank!
Promo code: dmay430offUKj One coupon per customer. Expires May 7 at 11:59pm.
START SHOPPING >> http://kobo.to/JYLrqn
It's just off books contained in the link... not their whole stock.
https://www.facebook.com/kobo