Measuring ROI: A Nonlinear Process
A nonlinear process requires you to identify a strategy/innovation that works, paired with a best practice that historically worked and an audience that's ready to embrace a combination of strategy/innovation/best practice. Make a misstep in any one of these areas and ROI suffers. This nonlinear process is challenging, because you never know the probability of success in your strategy, best practices or audience acceptance. You continually iterate seeking success, while all of the parts continue to move.
Back to my experiences on Twitter: I messed around with two moving parts. First, my nontraditional use of the microblogging platform actually yielded unanticipated success within a vocal minority of my audience. Second, I incorrectly applied a best practice (listening to my customers) to a minority of my audience. The combination of strategies yielded a listless following that stopped interacting. And if you're using Twitter, you know that without interaction you have nothing.
It's your job as marketers to realize that ROI is a nonlinear process, requiring strategic thought at each stage to yield success. Carelessly messing with a portion of the ecosystem causes the entire ecosystem to fail. Maybe it's always been this way, but with real-time interaction and measurement tools, it's easy to see how ROI can be suboptimized.