As the show has become popular, two websites have been created. NBC sells branded merchandise at its NBC Universal Store website. Its logo is prominently displayed in several locations in downtown Scranton, Pennsylvania, where the show is set. Since the show airs in many different countries, Dunder Mifflin has become associated with Scranton internationally – in a 2008 St. Patrick's Day speech in the suburb of Dickson City, former Irish Prime Minister Bertie Ahern identified the city with the company.
A fourth season episode, "Dunder Mifflin Infinity", said the company was founded in 1949 by Robert Dunder and Robert Mifflin, originally to sell brackets for use in construction. U.S. News and World Report likens it to many real companies in its size range: "It is facing an increasingly competitive marketplace. Like many smaller players, it just can't compete with the low prices charged by big-box rivals like Staples, OfficeMax and Office Depot, and it seems to be constantly bleeding corporate customers that are focused on cutting costs themselves." The show's creators share this assessment – "It's basically a Staples, just not as big", says co-producer Kent Zbornak – as do some of those companies. "Since Dunder Mifflin could be considered among our competitors", says Chuck Rubin, an Office Depot executive, "I think Michael Scott is actually the perfect person to run their Scranton office."
The company is depicted as based in New York City, with branches in smaller Northeastern cities. Episodes take place at the Scranton branch, managed by Scott (Steve Carell), but other branches have been mentioned. The now-closed Stamford, Connecticut branch was seen when Jim Halpert (John Krasinski) transferred there during the first half of the third season, before it was merged with the Scranton branch. Another episode, "Branch Wars", gave viewers a brief glimpse of the Utica branch, one of several purportedly in upstate New York. Zbornak says that city was on the short list for where to base the show, with some of its writers having ties to Central New York, and that they always intended for at least a branch office to be located there, for reasons of phonetics. "Utica was just such a different-sounding name than Scranton", Zbornak says. But also, "we had done a little research and thought our kind of business could survive in Utica."
A Buffalo branch has been mentioned in several episodes, and the fictional Dunder Mifflin website also lists a Yonkers branch. Albany rounds out the New York locations, leaving three other branches in other states: Akron, Ohio; Camden, New Jersey; and Nashua, New Hampshire.
Dunder Mifflin is also depicted as struggling to accommodate the demands of a diverse workforce. Episodes have focused on sensitivity training sessions and other informal efforts. Sexual harassment has occurred often enough, however, that it has lent its name to an episode. Employment lawyer Julie Elgar started a blog analyzing each episode for plot developments likely to be actionable if they occurred in real life and estimating the legal bill and/or possible verdict the company would incur should a suit be filed (as indeed Michael's former supervisor, Jan Levinson (Melora Hardin) did in one episode, alleging wrongful termination). Greg Daniels, the show's creator, said many episode plotlines are in fact based on anecdotes recounted during the sensitivity training he and the other members of the show's cast and crew are required to take annually as employees of a General Electric subsidiary. The episode "Boys and Girls" showed that the company strongly resisted unionization efforts by its employees, to the point of closing down a branch, as many real companies do or threaten to do in the same situation.
At the first annual The Office convention in Scranton in 2007, fans who had paid for reserved seating at an "uncommon stockholders meeting" in the Mall at Steamtown received an annual report and complimentary ream of paper. A nearby elevator shaft is also decorated with the company logo. While the Scranton branch's address, 1725 Slough Avenue, does not actually exist (the street name was invented as a tribute to the original British version of the show, set in Slough, near London), the company logo can be seen two places in the city's downtown section outside the mall: on one of the pedestrian overpasses along Lackawanna Avenue, and a lamppost banner in front of City Hall.
Two websites purporting to be the company's exist. Dundermifflinpaper.biz is the main site, with basic information about the company, and Dunder Mifflin Infinity, which is allegedly the company intranet, serves as a fansite.