I used to own an army of Orks that came as part of the Assault on Black Reach box. I also traded away the Space Marines to my big brother who is also a collector (And active hobbyist, even owns an Imperator-class Titan and a life-sized Space Marine helmet, not to mention a replica of Gandalf's sword, even though that has nothing to do with 40k) for his own box's Orks. I later on gave them to him as I realized I don't have the drive, will, or money to keep this army together. But I did obtain all the possible lore-books I could. I also own a large number of old White Dwarf magazines, including the 300th issue of it, which is still in good condition!
I am also an avid video gamer when it comes to the 40k universe. Dawn of War and all it's expansions and sequels, along with Space Marine, lots of the mobile apps, all of them have drawn me to them, including the upcoming MMO, Eternal Crusade (Which I cannot wait to play!).
All in all, I used to have some miniatures, but then I stayed for the lore. The universe fascinates me. In fact, the universe of 40k inspired my internet moniker which you see right now! I always had a thing for Space Wolves...
EDIT: However! If there is a way to play the tabletop game online, without having to buy the miniatures, I would get into it so bad I'd have to be pried off with a molecularly sharpened spatula.