Surely they do, all kinds of "cloud" companies were their favourite milking cows in the last decade. I believe Amazon's primary motivation for going as far as buying an own chip company was to, at least, send Intel a signal "would you lower the price tag?"
That "cloud" industry is approaching the point of market being fully served, and everybody starting to focus on price. Amazon surely wants to be at least prepared for that, if not having a plan to undercut everybody early on ARM based hosting.