I believe Medium is truly trying to boost the best pieces, and I have found there is, indeed, better writing across my feed since the program was implemented. Of course, it's all subjective. The payscale is also tremendously skewed toward boosted article; by my reckoning, a boosted article with the same number of reads and engagement from members earns 10 times more than the unboosted article. This makes it extremely difficult for an unboosted article to earn over $100.