With Fiber Switches extending the distances over 100km , supporting a remote site is more cost effective with a SAN. Also, with SAN Directors the distances are unlimited in WAN technologies (solely dependent on the networking technology) and maintaining a replica of data in remote data centers as well as local data centers is an advantage of SAN technology 

• Data Migration
  Legacy storage data can easily be migrated to new SAN storage utilizing SAN Directors without interruption to the Application Services.

• Remote Mirroring and Backup 
  Having remote replication has an additional advantage. The data at the remote site is backed up only without having to perform backup at the primary site (The mirror is broken with the primary site and the remote site to perform uninterrupted backups. Once the data is backed up at the remote site the mirror is re-established with the primary and remote site).