SpiderOak One and Groups are designed to synchronize files across your own computers, but not with other people. There are a couple of ways to share files with others, but neither of them provide two-way, read-write synchronization with non-users. They are:
A Sync lets others upload and download files into a shared folder, but with the limitation that everyone uses the same account and password. Families, small businesses, and small professional practices often do this. There are no limits to the number of computers and people using a single account. To set up your first Sync, see Syncing Your Data.
A ShareRoom shares a folder and its contents with other users or even with people who aren't SpiderOak One or Groups users and who do not have our software installed. The share is read only: other people can view and download files from it, but they cannot add files to it, and any changes they make to downloaded files from it will not be synchronized back. To set up your first ShareRoom, see Sharing a Folder.