I'm sure there are other folks on here who know more on the subject, but the last time I looked into data from that Tufts group, it smelled fishy to me: closed

I'm sure there are other folks on here who know more on the subject, but the last time I looked into data from that Tufts group, it smelled fishy to me: closed source analysis of closed source data. It seemed to hardly count as verifiable academic research. The raw data was seemingly made available privately to the researchers by way of their close relationship with the companies they're studying, the raw data is not made available by reproduction of their analysis, and there's no way for others to acquire similar data for comparison. They may be honest, and the data and analysis may be accurate, and it may not be trying to paint a picture that favors its benefactors, but I did not conclude any of those things.