Susan, sorry I'm jumping into this conversation a bit late (it's been a bizzee-day). There is absolutely nothing wrong with anything in your comments. We're all here to learn, ask questions, etc. so I'm glad you asked what you did.
Tess is right, I do have a few people who help me with some things - some things are my own and some are client things. I'm not a multi-VA firm though and don't really plan on heading that direction. Regardless of what I hand off I do quality control, follow-up, etc. and that time isn't billable. In 2012 I paid out about $22K as sub-expenses.
Of my almost $116K less than $900 was made during my short bursts of sleep - mainly affiliate sales for the few trusted products I mention in some blog posts and a gig on Fiverr.
Only about 60% of my daily time at the computer "working" is actually billable. So that makes for really long days. I'm fighting to re-gain my life. I'm almost 40 and would someday like to get married, travel a lot, etc. I've just recently quit working at least one weekend a month. My goal is to eventually not work on the weekends at all.
With the help of my business coach I'm hoping to work with more bigger clients - I have some that are less than $50/month. I also hope to develop some info products/training courses. And, of course I'll keep teaching the Virtual Assistant Business Jumpstart class for VAF/Tess.
I think your friend has the right idea regarding developing products and you'd want them to be consistent with what you offer so you aren't "buying VA advice from a dog trainer"

One of the things I mentioned during a recent brainstorming call with Tess is that I wish I had started developing passive income streams sooner.
Anyhoooo, I have to run out for an appointment. Feel free to ask any other questions you may have. Here to help!