The single-buyer model might be ready for the ash-bin of history, writes Tony Zambito. Focusing on the single buyer risks being excluded from a complex ecosystem that uses social tools and other technologies to share purchasing info. Deep knowledge of the kinds of people involved in your sales, along with predictive modeling, can help companies take advantage of the growing number of opportunities they face to affect a sale. "We are confronted with a world where buyers no longer act independent of others in decision-making ... The imperative for senior B2B executives is to adapt to change and make the tough decisions that come with change," Zambito writes.