What is the conversation mainly about?

W: What are you doing?
M: I’m ordering some filing cabinets out of a catalog.
W: What do you need them for?
M: There’s so much stuff piling up in my dormitory room. If I don’t do something soon, I won’t be able to move in there.
W: Do you usually order from a catalog?
M: Sometimes. Why?
W: Oh, it’s just in the history class today we were talking about how the catalog sales business first got started in the US. A Chicago retailer, Montgomery Ward started it in the late 1800s. It was really popular among farmers. It was difficult for them to make it to the big city stores so they ordered from catalogs.
M: Was Ward the only one in the business?
W: At first, but another person named Richard Sears started his own catalog after he heard how much money Ward was making.
M: What made them so popular?
W: Farmers trusted Ward and Sears for one thing. They delivered the products the farmers paid for and even refunded the price of things the farmers weren’t satisfied with. The catalogs became so popular that in some countries school teachers even used them as textbooks.
M: Textbooks?
W: Yeah, students practice spelling the names and adding up the prices of things in the catalogs.
M: Was everybody that thrilled about it?
W: That’s doubtful. Say they drove some small store owners out of business. Sears and Ward sold stuff in such large quantities. They were able to undercut the prices at some small family-owned stores.