Many Internet Entrepreneurs Have Learned That It Is Difficult to Beat

Many Internet entrepreneurs have learned that it is difficult to beat the forces of perfect competition.In perfect competition,there are many small stores with largely commodity products and low entry barriers.Which industry has got caught up in the Internet bubble and has tried to join with online models,most of whom closed after a couple of years?

A) Pet supply stores
B) Book sellers
C) Wine stores
D) Express mail industry