You really don't get it?
Well, how much do you think it costs to build a new store, maintain it, pay employee's, constantly train new employee's, deal with B&O tax, unemployment tax, Social Security, benefits, etc? Wouldn't it make more sense to sell online with constant promotions to get people away from your competition? It's working, OD just closed a bunch of locations, and others will follow.
It's really obvious here in Seattle where Staples doesn't have even one store, and the closest one is an hour drive each way if there is no traffic or rain.