Blog conversations are great, but those take an uncommon degree of chutzpah. Anyway, the point is to foster fruitful interactions (see infographic below).
Think about it from the visitor's point of view. It takes more time and more chutzpah for a visitor to comment on a blog post than to accept an offer to download or register for something. Does your typical customer have alot of chutzpah (like this gal impulsively throwing off a business suit to dive in)? For many of our clients the answer is no... which is fine. They may have lots of conversions without alot of blog comments.
Like any other marketing tool, a blog should pull its own weight. But what's the best way to measure the return on your investment of time and talent?
It ain't the number of comments people make on each post. And it ain't "raising awareness" either. (And maybe it ain't even a well formed question, per David Meerman Scott).
Tools like blogs should contribute to bringing about meaningful conversation with those who can buy, refer, or influence buying. For it to work, your content needs to be authentic and high quality. Easy to find. Easy to get. And genuinely useful. Companies doing inbound marketing for lead generation want to raise the incentive and lower the "friction" to the point where visitors take desired actions such as downloading a free set of tips, or signing up for a webinar.
In light of those methods and goals, the ratio of visits to responses -- the conversion rate -- is a key metric to track.
Being in the room
It's useful to draw an analogy between being in the room with a prospect, and having them at your website. High traffic and low conversions indicate a serious problem: it means you are "in the room" with hundreds of prospects, but after talking with you a bit, nearly all get up and leave without a handshake or exchanging business cards. But if your conversions are rising or already high, it means that after prospects enter your "room" they are shaking hands with you and exchanging business cards with you, leaving the door open to relationship development. (Of course we're assuming the contacts are in the target audience and not "duds.")
The chutzpah factor
Also think about it from the visitor's point of view. It takes more time and more chutzpah for a visitor to comment on a blog post than to accept an offer to download or register for something.
Also, the incentive to comment is relatively low. To comment, the visitor has to formulate his thoughts and contribute them for public consumption. Yes, there's the long term SEO benefit of back links... but there is no immediate tangible benefit to the visitor for doing so.
Particularly on a B2B site, visitors may be unlikely to comment. They may work at a large organization and perceive risk around leaving a public comment. (Eg "is it allowed per my company's social media policy? I'm not sure, so it's probably best to err on the side of caution and keep mum.") Their day-to-day work may not involve writing content for public consumption -- a skill that takes practice. They may prefer to absorb information rather than volunteer their insights or ask questions.
So don't worry if your blog isn't racking up a lot of comments. Pay attention instead to your conversion rate.
If you do get lots comments as well as conversions, that's great too. Notice I'm not saying comments are bad. They can challenge you and expose you to good ideas. In fact, whether you think I'm right or I'm crazy, I'd like to hear yours.