True USB Flash Drives cost much less and hold less data than Hard Drives. We see clients everyday that lose data on a Flash Drive they did not back up. Most clients think since they paid $40 or less for a drive the data is also less valuable.
The truth is that a .PST Outlook email database can be only a few GBs in size, but be worth several thousand dollars. An Excel spreadsheet or a Word document can be 64KB and worth a great deal to a client.
At 24 Hour Data we see that people put more value on Photos than any other data type. Storing pictures happens to be the main use for Flash media. Photos are a moment in time. Documents can be written again, but pictures are not that easy to recreate.
Flash media can be very expensive to recover. Sometimes costing several hundreds, even thousands in rare cases. The moral to the story is Data is valuable no matter what drive or media it is stored on. Backing up important data is the only way to insure data is not lost. The alternative is a high priced Data Recovery no matter what the media costs.