I'm one of those lurker types I rarely post. For the most part I just come here to find out information on upcoming releases. I found out about RPG's in PDF form from here starting with Malhavoc's stuff. Right now I'm making it my buisness to ONLY buy PDF's as opposed to hardcopies. I've posted my reasons on another thread, but I'll sum it up here as well.
1. I actually USE the stuff in the books that I buy. It's easier for me to cut, paste and modify from a PDF than it is for me to hand copy the same crap from a book.
2. I have a Laserprinter at home that allows meto print duplex (double sidede). So I can print out only the portions that I'm intersted in an make notes on those copies as opposed to marking up a hard copy that I paid anywhere from $20 - $50 for.
3. I have shelves of hardcopy game books and I've pretty much run out of space for new stuff. Last year I must have donated at least $500 in game books and suppliments to my local library. My PDF's all fit on my G4 PowerBook, My G4 imac, my two homebuilt PC's (one running XP and the other running RH Linux) as well as being backed up on CD-RW's.
Those are some of the reasons but ther eare a few more, including me wanting to give the middle finger to my LGS. I will not however by a PDF same price that I get it for in the store or ordering a hardcopy on-line. At that point I just do without the book. Green Ronin and HERO games putting out PDF's and DrivethruRPG having watermarking as an option were the two deciding factors in my decison to go PDF only. If it's a scanned PDF then the book is for the most part useless to me, pretty much any thing that interferes with me cutting and pasting from a PDF is something that, unless I REALLY want it, I will not buy.
I've dropped a fair to midding amount on PDF's over the past feew years, as soon as DTRPG is done watermarking all of their stuff there's gonna be a PDF buying rampage...