It's nice to see some in the VC community talk about sustainability. I'm skeptical that the greater early-stage investment market will ever get behind this idea unless the fund durations go well beyond the typical 5-10 year window. Sustainability takes time, and is inherently less risky than a more grow-or-die approach that many start-ups adopt. If you have to make returns quick, you're back to a strategy that is at odds with sustainability.