mreed - I am very impressed. May I make a few suggestions?
IMO, I think you should create a website for this service. Display your pricing packages and everything to clear up what the end user gets.
Create a testimony/samples page. With this testimony page, charge the user of your service $x amount per month (kind of like selling ad space). If you are positive you can get decent traffic to the site, then you could charge like $20 per person, and have like 10 spots filled. Now I feel this is a win-win for everyone. One, it is month to month, real life samples of your work. You provide an exerpt of the post, and have a "Read The Full Post" link. That link is to the actual post you wrote for the customer, like customer.com/sample-post-here/". So there is your sample, or testimony. Also the customer gets traffic. You get $20 a month per person. 10 spots = 200 bucks.
For the sign up page, you could simply allow someone to contact you, or inform them that you are not accepting any new customers at the time.
Add some hidden ways to monetize the site, like adsense, text links, or affiliate offers.
Just a thought. You said to earn a few bucks while building your empire, but this could be an empire on itself.