Amazon has rolled out a few helpful updates for its recently released business-focused Dropbox competitor, Zocalo, including a way to share files on its Web service simply by sharing a link.

Google has gone in this direction in recent months by emphasizing link-sharing in Google Drive. Dropbox and Box have long gotten people to view documents by way of sharing links, too. Even the startup Droplr pushes links. Now Amazon has stepped up with a link-sharing option of its own -- with just one caveat.

"The contributors must already be members of the site," Amazon Web Services chief evangelist Jeff Barr writes in a blog post today.

It's an interesting decision for Amazon to make. Mandating that people become Zocalo members means consistent usage of the service could increase, as pretty much all file-sharing companies want to become popular and well used. Then again, requiring membership does feel a bit like a throwback to the time before Dropbox and Box pushed consumer-friendly applications that let people share files no matter what company they work for.

Other new features include multi-factor authentication and a "decline feedback" button for users who have nothing to add once colleagues have asked them to contribute their input.