In the physical world, preservation sometimes involves modifying or restoring a piece to some extent, in order to prevent further decay. In the digital world, this is not quite as necessary, as usually we're transferring from physical media (VHS, etc) which could decay into bits. Great, except that transferring something to digital media does not really ensure preservation. Digital files are stored on physical media, usually HDDs, and physical media can decay, either from calamity or age. As such, the only way to truly ensure digital preservation is to ensure that the files will survive both disaster and time. The easiest way to do this is continuous distribution, so that the files are stored in many places, and are continually being stored in new places.

If your preservation isn't freely available, it's probably not very well preserved.