Maybe those better online prices do come at a cost-pollution. Some saying significant increase in cardboard over the years. Also just a potentially damaging is the delivery trucks creating air pollution(along with putting more weight and wear on roads).
http://consumerist.com/2016/02/16/our-growing-e-commerce-addiction-means-mountains-of-cardboard/
http://consumerist.com/2016/02/16/our-growing-e-commerce-addiction-means-mountains-of-cardboard/