A reputable supplier uses software which encrypts the data on your PC using a key known only to you so that it is safe from prying eyes while on their servers ...... that is the theory anyway.
If they use data de-duplication then this approach clearly doesnt work.
The automatic corporate backup on our PCs at work does use de-duplication but the company has its own backup servers. For domestic use encryption is a key requirement so de-duplication cannot be used and no reputable supplier advertises it.
At the end of the data the data MUST be backup up somewhere safe off-site on a regular basis. This means it must be automared.
Ex <n>ildram , been to SKY MAX - 15,225 Download
BE Unlimited - 21,000 Download 1,200 Upload ON THE LINE THAT SKY COULD ONLY PROVIDE 15,255 DOWN AND 800 UP ON!!!,
Moved house, now BE Unlimited 6,500 Down, 1Mb/s up - gutted!
FTTC Cab installation commenced 12th April - expect full 80 / 20 - bye bye BE, hello BT Infinity soon!