When we committed Thinkshift Communications to working only with sustainable businesses, cleantech companies, and social enterprises, some people (our attorney, for one), thought we were nuts. A decade ago, companies in our potential client universe were definitely not on the unicorn track. B Corps and prioritizing anything above profit were mysterious concepts. Impact investing was a nascent field. But we had a mission — speeding the shift to sustainable business — and the obstinacy of true believers. A decade ago, companies in our potential client universe were definitely not on the unicorn track. B Corps and prioritizing anything above profit…