That or Backblaze business model where they are betting that most costumers won't utilize more than their profitability ceiling

I believe it is the former though

Imagine a kebab shop with a fixed capacity of producing one kebab per day with $1 COGS. They sell a package for "unlimited kebab" to exactly one person for $8 per week

At worst they will be gaining $1, the profit is when their singular costumer doesn't feel like eating kebab that day

Quoting Linus (the plane guy, not Torvalds) that's just a simple girl math but you got the gist