Worth thinking about this in the context of fat-head vs. long-tailed distributions, or less formally "whales". A very small number of users (the "head" or "whales") can account for most of the area under the curve, which in this case is the cost of delivering free build minutes.
For a toy example, imagine one user uses 2k minutes, 10 use 100 minutes, and 1000 use 1 minute. In this case you have "Over 99% use 100 minutes or less", but 50% of your cost is going to the one 2k minute user.
I have no idea if this is their exact curve, just showing how a fat-head distribution could explain what they are saying. I'd expect the "demand" (i.e. minutes used if they were not constrained / all paid for) to be a power law distribution.
Also worth noting that there's a sort of bimodal selection effect going on here -- it's unlikely that you use exactly 2k minutes/month, since you'd be hitting your limit and that would be disruptive. So the closer you get to using 2k minutes, the more likely you are to pay for more than the free tier. So I'd expect this pricing change to also force some users that were previously on 400 minutes +- 100 to have to upgrade too; this will impact some of the 98.5% of free users that are using <= 400 _on average_ per month.
For a toy example, imagine one user uses 2k minutes, 10 use 100 minutes, and 1000 use 1 minute. In this case you have "Over 99% use 100 minutes or less", but 50% of your cost is going to the one 2k minute user.
I have no idea if this is their exact curve, just showing how a fat-head distribution could explain what they are saying. I'd expect the "demand" (i.e. minutes used if they were not constrained / all paid for) to be a power law distribution.
Also worth noting that there's a sort of bimodal selection effect going on here -- it's unlikely that you use exactly 2k minutes/month, since you'd be hitting your limit and that would be disruptive. So the closer you get to using 2k minutes, the more likely you are to pay for more than the free tier. So I'd expect this pricing change to also force some users that were previously on 400 minutes +- 100 to have to upgrade too; this will impact some of the 98.5% of free users that are using <= 400 _on average_ per month.