I whole heartedly agree with the author of the article GE, thanks for sharing it. Many many MANY moons ago, I began an all volunteer organization. I got a lot of attention but was never paid for my efforts. I managed a large staff, recruited planned events wrote everything from brochures to press releases and just generally became comfortable with lots of unique and varied skills, all volunteer.
Couple of years later I was in a fairly dead end job (even altruism has it's limits and my kids had this funny habit of requiring me to GET paid so they could have little things like food and shoes) anyhow an opening came up for a position as the assistant to a very high powered, high profile, individual within the same company. I restructured my resume to include all the volunteer experience I'd managed to accumulate targeted the resume to her to include "professional references" from my media contacts, since I knew that would be a hot button...
And got the job.
I've told others in the past that volunteer positions are often valuable sources of proof that you have real world skills that you were not currently using it IS one of the many pathways to promotion. Im living proof!