The point is that if you have a 10% chance of frying motherboard, at 10 a week, you might expect 1 fried p/w, but it could easily be more which may be catastrophic.
At 1000, the number of fried boards will be more predictable and therefore the risk to the business is lower, even if the long-run averages are the same.
At 1000, the number of fried boards will be more predictable and therefore the risk to the business is lower, even if the long-run averages are the same.