The children's war novel 'War Horse' by Michael Morpurgo for Kindle is an Amazon Kindle Deal of the Day.
Upon ordering I received the below message:
'You have received a promotional credit of £1 toward the purchase or rental of a movie, TV season or TV episode from Amazon Video.'
So you could receive this if you haven't made a qualifying purchase yet.
'The book that inspired Steven Spielberg’s Hollywood blockbuster movie and an internationally acclaimed stage show . . . it can only be Michael Morpurgo’s War Horse.'