For mission-critical systems and business continuity, disaster recovery systems must be fully advanced as long recovery times are unacceptable. The gap between RTO (Recovery Point Objective) and RPO (Recovery Time Objective) must be minimum.
Continuous data protection eliminates the problems associated with the backup window, which creates very frequent, block-level backups rather than nightly backups. Every few minutes newly created or modified storage blocks copied to the backup targets like storage arrays or remote machines. Thus, reducing the recovery point objective (RPO).
Losing a few minutes data is more affordable then losing a data of entire day.