I just looked at an email from Kobo that offers a free book after buying a Glo HD or Aura H2O. The email links to
https://www.kobo.com/MothersDayoffer with the explanation. In the fine print, there is "eBook offer consists of a user’s choice from a selection of eBooks found at www.kobo.com/MothersDayredemption". The last bit is a link, but the URL is
https://www.kobo.com/www.kobo.com/MothersDayredemption. That doesn't work.