i too own a copy of the game without paying for it. however, now that i've seen how great this game is, it's certainly worth my money, and i'll purchase a copy soon. this is what i do with most games, since often they don't live up to my expectations and i eventually delete them. i'd hate to have shelled out $50 for something i didn't want.
i can see where your friend is coming from. if i find a game i love, i want others to see what's so great about it, and maybe even get them to play it with me online.