Originally Posted by Andrew H.
I think the formulation "has been allowed to grow unchecked" is strange in this context, as it seems to suggest that someone should have stopped Amazon.
Despite Amazon's very strong market position it has been allowed to buy competitors like "The Book Depository" and to join up with Waterstones for selling ebooks. Even companies that have achieved a dominant market position all on their own can be subject to restrictions to avoid abuse of their dominant position.
As to the argumant that Amazon is a stronger postion vis a vis Random House Penguin that is debatable. While it is not as large as Amazon Bertelsmann isn't a minnow and there are markets where a loss of the Random House Penguin / Bertelsmann books would massively damage Amazon's standing in the market place.