I think its more the long run you should focus on, not the shortterm value. Quality and Consistency are the 2 main factors to success. Compare it to SEO. The best SEO doesn't help if your content is not worth a penny. I believe in that. How does it fit in this discussion? Well engagement comes first, since you shouldn't really focus on reward, more on delivering value!
RE: Which came first, the Engagement or the Reward?