I recently posted a comment to Joe Jaffe's blog about Second Life as he is getting a lot of feedback about the pro's and con's of Second Life. From what I can tell, well-meaning marketers are still feeling it is something of a scam. I guess it is all in how one looks at it. We are quite bullish about 3D worlds in general, as long as one knows what they are getting in to at THIS STAGE OF THE GAME. That part is key:

I want to step in here. I work at a digital marketing agency that is spending quite a bit of time and internal capital on building a practice out of Second Life. It is just one of our practices, the others being more well established digital capabilities. Second Life is an early adopter experiment. It is a place to demonstrate the power of a 3D interface and content without being someone's beta product. If you are a client that needs to demonstrate complex visual models or ideas, it is a great space. If you are a client that wants to create an event but the constituents are narrow and worldwide, it is a great venue. If you want to demonstrate that you are exploring all forms of digital communication, then it is a low cost demonstration. Sun, Sony and others are also working on new 3D environments. But what they are missing is an audience. Second Life has the advantage of having real people constantly pushing the buttons and testing the limits. As far as ROI, the ROI lies in what would the difference be between building the kinds of things (an event, a model, a demo) in the real world vs. a 3D virtual version? Huge. And what is the impact when the right audience can now really "get" the complex idea? Really huge. So change your perspective. This is not a full mass market medium yet. It is a sandbox. A really cool, public sandbox. If you look at it this way (for now anyway), Second Life has all kinds of possibilities for the smart marketer.