What are the advantages of strings for serialization?

What's wrong with binary files for serialization?

Solution

String data is human-readable, which is wonderful for troubleshooting. Binary data is not.
String data is easily parsed by systems on any platform. Binary data is not always, so if you need to pass data between a Windows and a Linux box, or maybe an IBM Mainframe, string data is simpler.
String data also is comprehensive enough to include XML, which brings even better features to the table.
It's easier to truly encrypt and decrypt, particularly if you're going cross-platform.

However, there are disadvantages to using string data as well.

It usually results in larger amounts of raw bits - larger files, more traffic on the network, etc.
It's human-readable which is not so wonderful if you need to protect it from being used in other systems or from prying eyes. (Although encryption helps with the prying eyes deal.)