Nice post. The CTP crew teaches that it's a 4:1 ratio or so: pull people with value-laden content on your blog, etc. Then, in a 5 day email exchange, the 5th one would be the recommendation\link to where folks can learn more.
In your TV analogy, I wouldn't watch 100% ad tv. no point.
Great job pointing to benefits instead of features too (for those reading this who are marketers)