Location and role in the series
It is fictitiously located on the corner of the real-world 3rd and Pike Streets in Seattle and is portrayed as being just across the street from the also fictional KACL Radio Studios. As such, many of the KACL staff go there during their free time, including Frasier Crane and his family. In the story the cafe has a number of regulars, including the Crane family and friends, and it is where Frasier and his brother Niles Crane meet to discuss various topics, often joined by their father Martin Crane. It is a prominent location in the series, and the episode "My Coffee with Niles" was set entirely within the cafe.
The producers of Frasier decided that a non-work, non-home setting for Frasier should be a coffee shop, as Seattle is well known for them. They also made sure there were no stools (only chairs) in the cafe, to differentiate it from the Cheers bar back in Boston, where Frasier Crane had previously resided.
The cafe's name, Nervosa, is a feminine Italian and Latin adjective, meaning "nervous", as well as a psychological term meaning "the debilitating psychological addiction to an object, belief or behavioral pattern". It can also refer to "coffee nerves"—a condition caused by drinking too much coffee. On a tenth season episode, the coffee shop was revealed to be named after its owner, Maureen Nervosa.
The staff of the cafe has changed over the years, although one waitress (whose name was never mentioned, but who was portrayed by actress Luck Hari) was there for 4 years and in the later seasons of the series, a waiter named James was a permanent fixture at the cafe. Rick, the father of Roz Doyle's daughter Alice, was a cafe waiter and saved the money he earned there to study in Paris. One episode features Collette, an inveterate gossip who was in on KACL secrets that even Frasier and Roz weren't aware of.
Waitress Kit, a "free spirited" young lady, dated Niles Crane in the final two episodes of season 6, entitled "Shutout in Seattle". Waiter Eric dated Daphne Moon for a while, and her mother Gertrude got a job there when she moved to Seattle. An enormous young man named Chad was "the one who doesn't react when his arm touches the steamer nozzle", and Frasier attributed insipid latte foam to "Chad being back on steamer duty". Big guy, Paul Cosamano played an uncredited barista who, although rarely ever speaking a line, appeared in almost every scene set in the cafe throughout the run of the series.
Pauley Perrette (credited simply as Pauley P.) did a two-episode stint as waitress Rebecca in season four.
There are actually four different versions of the cafe. The "big" cafe shows several tables, the front door, the counter, and is meant to represent the whole cafe. The "medium" cafe eliminates the tables that are to the right of the counter (from the perspective of someone facing the front door). The "little cafe" only features the small reading lounge area of the cafe. When this set piece is used, waiters and waitresses approach the tables for orders, rather than receiving them at the counter.
There is also an outside view, which includes several tables in a patio-like setting. This structure features in several episodes, including "My Coffee With Niles," (they find a seat outside, but it begins to rain shortly after) "A Word to the Wiseguy," (where Frasier and Niles meet Gerome, a mafia-type figure) and "A Cranes' Critique" (where Niles, Frasier, and Martin have coffee before a shopping trip and first spot fictitious writer, TH Houghton).
Also in the series is one scene in the men's bathroom when Bebe is attempting to lure Frasier back to her agency.
There is, in fact, a coffee shop at 3rd and Pike in Seattle. It is a Starbucks.