Computer Files Backup - Do you use one?

[ghosthunter]

For personal files, I backup on a DVD. So far, I need only one DVD for them.... Tapon lang every month....

For emails, backup on a DVD... I do this every quarter.... Retention period is one year....

Won't it be better to use a 4gb USB flash drive for the above mentioned back-up jobs?

I have encountered that some DVDs (or DVD-RWs) I have burned as backup have a tendency not to be 100% readable after a few weeks/months.