There's also another, intrapersonal scale at play: if you get 20 "free" subscriptions, in 3-4 cases you'll definitely forget to unsubscribe before it starts cha

There's also another, intrapersonal scale at play: if you get 20 "free" subscriptions, in 3-4 cases you'll definitely forget to unsubscribe before it starts charging, since it becomes impossible to track and optimize every process. Attentional impact of each one is miniscule, so many people don't notice going way above 2% or any other hard limit they could probably deal with semi-efficiently.