This is why:

When you upload a file, you will realize that there is not much difference between CDClick i-Studio Transfer Guard® and another similar one using plain FTP. What is for you to see, is displayed on the monitor, but what is hidden is making all the difference.

TransferGuard®  features:
1. Resume automatically interrupted file trasfers.
2. Bandwidth control. 
3. Guaranteed CD/DVD/BD file transfer integrity.

TransferGuard® controls the copy speed and maintains its own log for errors. Because of its speed and very high reliability, TransferGuard® is especially well suited for the transfer of gigabyte-sized files.
During transmission, TransferGuard® performs block level checksum. After transmission, TransferGuard® checks the transmitted file size against the original to ensure complete transmission. In the event of an error in file size or a checksum error, TransferGuard® automatically retransmits the corrupted blocks. In the event of a broken communications line during transfer, TransferGuard® automatically reestablishes the link and completes the transfer from the point of interruption.

In addition, CDClick i-Studio incorporates specialized compression utilities for the compression of large ISO file images thus cutting dramatically transfer time.