I've got a few suggestions below; nothing urgent, and nothing in the docs is wrong.

Currently, the write concern docs do not mention bulk updates, and the bulk docs don't mention the purpose, either.

I would suggest adding a section to the write concern docs to say something like "If the overhead associated with getting acknowledgment for each write is a concern, you can amortize your write concern over up to 1,000 write operations is to use MongoDB's Bulk objects."

I might also suggest, on the Bulk() page, leading with something similar, like "Bulk operations are used to amortize your write concern acknowledgment over up to 1,000 write operations at a time."

Lastly, it might be a good idea to move the Bulk() operations page closer to the root of the reference tree, swapping places between Bulk() and the Bulk Operation Methods, which is just a list. Notice that, on the left, under 'Reference,' the operations list is closer to the root.

Hope the suggestions are useful!

-Will