I could start with my definition of new media communication tools, but if I can't prove that they can serve the marketing needs of the B2B community, who cares what they are. So let's start with metrics.
How many impressions? Pageviews? Clicks? Hits? These are questions that are now (or will soon be) irrelevant. At the end of the day, who cares how many people saw the full-page ad you ran in the trade publication that is now gathering dust on an end table in your reception area? Publishers of trade publications, maybe. Who cares if your podcast is heard by 2 million Chinese nationals who have no desire or ability to buy your product or service? Is that worth more than having the same podcast delivered to 100 top industry insiders who get paid to purchase products like the ones you offer?
Lest you think that I'm just trying to redefine the playing field to increase my chance of scoring, I should tell you that a lot of people are talking about this right now. Jeff Jarvis has a great blog post on this that points to a number of these discussions. I found it through a post on Dennis Haarsager's Technology 360 Blog.
I'm not suggesting that you stop trying to figure out how to determine whether you're getting a good deal on the promotional efforts you employ. Just make sure you're measuring the right metrics. With new media, it's not about throwing your message to the wind and hoping some of it lands in a prospect's ears. It's about telling your story to the people who want and need to hear it and engaging them in a conversation that will lead to a sale and an ongoing relationship.