If you've ever written for a blog with any regularity, you know that comments are golden. Everything we try to measure with email is evidenced in the comments fields of blogs. With just a few responses, authors can be assured of engagement, attentiveness and action, and also know whether or not their content has been targeted and effective. From a handful of comments, you know if the blog you wrote just nailed it. Despite all our metrics and measurements, I'm not wholly convinced the equivalent sensation exists in email marketing. (Debate may ensue: please use the comments field below.) But what if email did have a comments field? I'm not proposing a technology innovation; rather, a strategic use of imagination. If the emails you write and distribute to your subscriber lists could capture comments as easily as blogs do, what would your subscribers say in them? And what would the comments themselves say about your email marketing program? This is a point worth pondering, I think, since it helps to gauge the impact of an organization's email beyond its measurable metrics. Email is a powerful extension of a brand, and its qualitative aspects are often overlooked in exchange for its quantitative value. So play along. Which of these best describe the types of comments your emails would generate? Additive Replies: Would your subscribers share their experiences on the topic of your email, further educating other readers why they should buy this product, attend this conference or book that vacation? Have you built a community quick to chime in and participate, acting as advocates on your behalf? Clarification Questions: Are your subscribers likely to respond with questions, seeking more information or qualification? Is your brand approachable and inviting? Chatter: Will the comments start a conversation between your subscribers that's not necessarily about you, even though you may be invited to participate? Is your brand a conduit, enabling peripheral connections between your customers? Anonymous Sniping: Do you fear negative feedback? Are you over-mailing, or relying too much on metrics-lifting tricks? Trackbacks and Mentions: Is your content anticipated and inspiring enough to get passed around the blogosphere and twittersphere -- and, um, facebookisphere? Abundant: Is your subscriber base connected, motivated, engaged? None: Or is it just a list of people whose email addresses you have? Much of email purports to be part of a dialogue or conversation. Mountains of click-through and conversion data support this assertion; "do not reply" sender addresses and auto-responders work to undermine it. If your entire email channel could be transported magically into a social channel, would it flourish or flounder? In today's digital marketing, conversation is currency. How rich is your email?