My free daily letter doesn't have comments. I untethered from them.
However, that doesn't need to stop you from having a discussion around the content.
You can always link in to the post from your own blog.
Here's another idea: why not gather a discussion on your own social network page?
If I find an idea or a blog post that I want to discuss in more depth, here's what I do.
- Share the URL on a social network.
- Ask underneath: how was your experience?
- Comment with my experience under that shared item.
You can do this on any network. I'm using Google+ here as an example, because it's the only social network that I'm currently a part of. Google+ is also very good for starting gatherings of this kind, because the service promotes gathering for discussions.
Ev Bogue