This site for Shakespeare essays (that is, essays on Shakespeare, not essays by Shakespeare) is an example of the good and the bad side of the Internet. On the one hand, it is good because many of these essays are genuinely helpful and come from a variety of backgrounds and serve a variety of purposes. On the other hand, many of the links are dead.
One could go to a traditional library and find a fifty year old essay stowed away somewhere in a bound collection of journals or on microfiche. Today, the 'net is hit and miss. Something that might last for five years suddenly disappears one day and you can't find it anymore.
The 'net brings us some good stuff, but it is also curiously impermanent in some ways. It is transitory like the computer technology itself that has to be updated every five years (or less) at enormous expense, whereas the books waiting in the library can be cracked open even if they haven't been touched in decades. Can one ever expect a server, a hard drive, or a cd-rom of today to be accessible in fifty years? They will all be in a landfill or an attic or a museum somewhere.
Just some thoughts.