I just found out about this. If you don’t know, DriveThruRPG is a place that sells PDF version of role-playing books. Why is this important? Why do you want to spend money on a version of a book you can’t hold?
DriveThruRPG.com
Well First, it’s the only legal way you should have digital copy of an RPG book.

Secondly, They are often already cheaper than the regular book. For example, the new World of Darkness: Mirrors PDF is $22 versus $32. You get the same information and you shave $10.

Third, You don’t have half a dozen books on your shelf taking up space. now you, as a GM can take a laptop and a flash drive to the game session. Hate looking through a book going “I know there’s a rule about…” do search!

I have just about everything I need for Shadowrun on a 2 gig flash drive. Have you ever been on break, at work or school, and gone “If I just had my book with me…” There you go!

Now, all this can be yours with an extra 25% off.

Seriously why are you still reading this?

Did I mention they have free stuff too? This site just rocks.