As the creator of hnsummaries.com and former founder of a news summaries business, seems like a nice middle-ground would be to give the user an automated summary and then let them edit it if they choose to do so. As we moved towards this model, we were able to be much more efficient (we were doing it internally though).

You have a chicken-egg problem with real contributors (my guess is that you're bootstrapping the content with editors?). Am excited to see where this goes!