Kobo US has a gift card offer right now for Mother's Day, through May 15. It's buy $50 get $10 bonus, and seems to be pretty much like all the other recent similar offers. I suspect, but am short on time and can't check, that there will be a similar offer at Kobo UK, and maybe elsewhere. Although perhaps not, since not sure Mother's Day is the same in the UK???
Anyway, here's the US link to the Kobo gift card page, and the offer just shows up for me as a banner ad, a little ways down in the page:
https://www.kobo.com/us/en/p/giftcards