Ditto. I only read and play videogames. There's not much to spoil about books unless you actively go to websites discussing the title in question so book spoilers are rarely a problem for me. As for videogames, I actually go out to read up guides; I can't afford to spend days blundering around to find all the secrets and stuff unlike back when I was in school.
Does it detract from the experience? Perhaps, but the flipside is to play the game until the end only to realise I missed out on a whole bunch of stuff (too many games have low replay value, it's generally not worth the effort to play it again just to get what you missed before). Hence, guides. Sure, I'd appreciate it if the spoilers were kept to a minimum, but I wouldn't complain if the only guides around were full walkthroughs.