It really just takes a certain kind of person. I've had some friends that didn't read it for years and then finally meandered through it on a whim and were huge fans, and I've had a friend that read it all in one week during a holiday, said "it was interesting!" and then never mentioned it again T_T. I think it's important to understand that it is going to be a heavy investment so you have to consider if they're the type to actually enjoy it after putting in all the man-hours or not... Otherwise, tease and talk about the parts of it that you think would appeal to them!