I know why I have no comments in my blog: You have no time to visit this page, read it and certainly write an answer. That's easy and is okay.
So why can't we eliminate these unnecessary steps "Visit" and "Read", leaving only a "Post Comment"? We have some time traveling to work and back... Honestly, I prefer listening audio books while walking back home (if there is no good company to share my walk).
Here is the idea: Provide real-time podcasting service to bloggers/news sites. In the morning site visitors could select blogs/news/articles they would like to listen to and receive narrated version in the evening. Or visitors could subscribe to audio-version of a blog (eliminating "Visit" step).
You can outsource this service to India/xUSSR/China. Of course narrators should have great speaking skills.
How can this bring money? Easy: context audio ads are more than suitable here...
Unfortunately I cannot give you narrated version of this post... yet :).