“We have been humbled by our experience,” Ms. Medvitz said. “Growth in consumer awareness is slow, and that’s exactly what the wholesale channel offers: scaled exposure at a faster pace.”

It is easy to see why a new apparel brand might want to avoid selling to department stores and boutiques. “The shirt you bought for $70 in Nordstrom was made for $7 or $8. The rest of the money is chewed up in margin and markup that is of no benefit to you,” said Bayard Winthrop, who introduced the American Giant sweatshirt brand as a Web-only company early in 2012. “We thought if you could address that $60, you could deliver a better quality product with a better customer-service platform.”

Those who sell to department store chains not only have to accept low margins, they also often find the rules complicated and onerous. The chains may demand money for advertising, an unlimited right to return orders and the right to pay suppliers less when merchandise is marked down. In addition, the chains have suffered a generation-long decline in market share — from as much as 10 percent of the retail market in the 1980s to 2.4 percent in 2010, said Craig Johnson, president of Customer Growth Partners, a market research firm based in New Canaan, Conn.

“What the department stores used to be able to deliver was credibility to your brand,” Mr. Dion said. “But what a lot of these new brands have discovered is that the price that they have to pay is draconian. It’s become almost unprofitable to pursue department store distribution.”

When Brian Guttman founded a men’s clothing brand, Jeremy Argyle, in 2009, he steered clear of department stores. “I saw the challenges of being at the mercy of the large department stores,” said Mr. Guttman, 33, whose family spent more than 60 years supplying department stores with private label clothing through a company based in Montreal, Paris Star. Jeremy Argyle now operates two stores in New York. While it sells wholesale to a handful of boutiques, 70 percent of its $5 million in 2012 sales came through its own stores and Web site.