The amount of digital content available for RPGs is crazy. There’s just tons of it. I just saw a blog post on the site GeekNative that had a tally of something like 1700+ free RPGs. That is crazy pants. Just about all of this stuff is listed as a PDF only though.
Which makes sense. Take away the publishing costs and the Internet becomes a pretty efficient way to distribute content. The problem becomes the actual game use.
For my part, I find PDF gaming texts very efficient to transport, and relatively simply to read. However, to search and use for an actual game they can be a bit cumbersome.
During a session with my last static group, we tested whether it was faster to look stuff up in a printed book versus a PDF. The physical book won. It was easier and faster to go to the index or table of contents and search out the specific ideas. Searching the text for a specific word just wasn’t faster and easier. Maybe other people have different experiences, but that was mine.
In the end, I find them useful in their own ways for completely different purposes. PDFs are just infinitely more portable than physical books. Gaming books tend to be substantially large books. Not always, but often that is the case. At the same time, even if they’re bigger, they tend to be more useful at the gaming table. Just something to think about. Eventually this debate won’t matter, but for now, gaming offers different ways to get material. Different ideas for everyone.