“In our view Amazon's actions are not in the long-term interests of the reading public or the publishing and book retailing industry, globally,” Indigo vice-president Janet Eger said in an e-mail, adding, “Indigo Founder and CEO Heather Reisman has congratulated Barnes & Noble for taking a leadership stance on the matter, and offers kudos.”
The 3 majors, with around a thousand stores between them, are also joined in this by probably about an equal number of indies. (No clue on how many indies, but it's bound to be high.) So what we have here is a protest that has grown beyond one of the majors fighting with another; this has now become a genuine boycott of Amazon publishing.
I must say that I find this amusing. Amazon wants to be disruptive force in any industry they enter. But by entering publishing, they have become a unifying force for booksellers. Everyone hates their guts. Angry mobs might not hold together long, but they can do a lot of damage before they split.