Because it's revenue. If I spend $10 to acquire a customer worth $50 in revenue, my revenue is $50. If I spend $150 to acquire a customer worth $100 in revenu

Because it's revenue. If I spend $10 to acquire a customer worth $50 in revenue, my revenue is $50. If I spend $150 to acquire a customer worth $100 in revenue, my revenue is $100. In the second situation I have twice as much revenue. The fact that that revenue has been heavily subsidized and isn't profitable doesn't make it any less "revenue".