Considering the cost of hardware around 1.5M Sat and the expected lifetime of hardware as 5 years, a 10 M Sat node would need to earn 300_000 Sat a year (1_500_000/5) or 2,500 ppm (300_000/12/10) net profit per month to recover the investment. Assuming the node can route 100% of the local balance in a month, the node would need to earn 2,500 ppm net fees for each routing. In the same situation, a 100 M Sat node would need to earn the same 300_000 Sats a year but it drops to 250 ppm (300_000/12/100) net profit per month to recover the investment. Assuming the node can route 100% of the local balance in a month, the node can be profitable with just 250 ppm net fees for each routing.