It seems to me that, if you have to give away your labor for free to get your foot in the door, you have picked a career that will not go well. Even once you get a job, you may have to keep schmoozing and have "sharp elbows" to keep others from taking it from you. If you have to give away your labor to get started, that is valuable information in and of itself, but not in the way the author intended, I think.