I think it heavily depends on your product. If you have something that can be used by a single person (or small group) without a million others to use it, too, than you're IMHO default alive (Slack, Trello, ...). I think as a rule of thumb if you have to first get traction and then be able to monetize than you're default dead. Instagram's social component was default dead but the feature where you can alter your photos was default alive and that pulled them through.