Kobo US and UK both have a buy 60, get 10 offer (dollars or pounds) right now on gift cards. In both cases it’s good through April 1, which means it’s been around a while, since these are usually good for several days. I never saw a splash/banner or email for this, but since I’m using Kobo more and more, I went and looked, and there this was. So now you know. 🙂
The offer is just on their normal gift card pages, and you have to be a bit careful – the default amount for gift card purchase is not $60 or £60, so you have to change that before you buy!
Kobo US: https://www.kobo.com/us/en/p/giftcards
Kobo UK: https://www.kobo.com/gb/en/p/giftcards