When to Make Money off your Podcast?

[Jim Froehlich]

Podcasters...for anyone breaking even or actually making money off your (real estate related) podcast, I'm wondering if you can point me to ideas on how best to grow number of listeners, if and when to add advertising, and generally how many downloads/listeners you achieved before breaking even?  In general, I'm not expecting to make money from podcast itself, but after starting one, I really like it and am thinking I should at least make sure it breaks even (and that means when calculating in my own cost/hr of what I think my time is worth! ... as my wife reminds me about taking another "hobby" too far...hah)

Anybody know of a good post on this subject or even a book?