I would call this simple economics, as price and costs of operations come down, the cause stimulates an effect on demand, suppliers are now competition, like the credit card free of annual fee model, all suppliers are under pressure to follow suit, now all citizens feel free to go for credit cards, demand gets stimulated, the same principle is applied by Fed on interest rates.

Arvind Pereira
http://www.ArvindLeoPereira.co.nr