Sears was one of if not THE first nationwide chain and revolutionized how America shops. Outside of the big cities, if you needed something you ordered it from the Sears and Roebuck catalog. People would wake up in Sears and Roebuck beds and bedding, eat their breakfast on a Sears and Roebuck table using Sears and Roebuck silverware, then put on their Sears and Roebuck shoes and go to work.
I still remember spending hours checking out all of the cool shit in their catalog when I was a kid and you can find scans of catalogues from the mid twentieth century that are really interesting. They weren't free like catalogues today, you PAID for the honor of buying their shit and were happy to do it.
Surburban sprawl and the strip mall phenomena killed the mail order business. People could get whatever they wanted whenever they wanted it. They just didn't evolve with the times.