1. A lock file that works well. My team spent countless hours dealing with strange npm shrinkwrap issues beforehand. The fact that it uses a lock file by defaul

1. A lock file that works well. My team spent countless hours dealing with strange npm shrinkwrap issues beforehand. The fact that it uses a lock file by default is also nice, since people don't have to remember to update it after adding or removing a package. 2. Deterministic installs (running install with the same lockfile will result in the exact same node_modules). With npm, we ran into issues that would somehow be fixed after deleting the node_modules directory and reinstalling everything. That worked far too often. 3. The offline mirror. This gave us a reasonable method for checking in our packages to our Git repo, meaning we could build our site without an internet connection. It basically fixed all of our issues with npm, saving us hours upon hours of time.