A soap opera is a radio or television serial dealing especially with domestic situations and frequently characterized by melodrama and sentimentality. The term soap opera originated from radio dramas being sponsored by soap manufacturers.
A crucial element that defines the soap opera is the open-ended serial nature of the narrative, with stories spanning several episodes. One of the defining features that makes a television program a soap opera, according to Albert Moran, is "that form of television that works with a continuous open narrative. Each episode ends with a promise that the storyline is to be continued in another episode". In 2012, Los Angeles Times columnist Robert Lloyd wrote of daily dramas,
Although melodramatically eventful, soap operas such as this also have a luxury of space that makes them seem more naturalistic; indeed, the economics of the form demand long scenes, and conversations that a 22-episodes-per-season weekly series might dispense with in half a dozen lines of dialogue may be drawn out, as here, for pages. You spend more time even with the minor characters; the apparent villains grow less apparently villainous.
Soap opera storylines run concurrently, intersect and lead into further developments. An individual episode of a soap opera will generally switch between several different concurrent narrative threads that may at times interconnect and affect one another or may run entirely independent to each other. Each episode may feature some of the show's current storylines, but not always all of them. Especially in daytime serials and those that are broadcast each weekday, there is some rotation of both storyline and actors so any given storyline or actor will appear in some but usually not all of a week's worth of episodes. Soap operas rarely bring all the current storylines to a conclusion at the same time. When one storyline ends, there are several other story threads at differing stages of development. Soap opera episodes typically end on some sort of cliffhanger, and the season finale (if a soap incorporates a break between seasons) ends in the same way, only to be resolved when the show returns for the start of a new yearly broadcast.
Evening soap operas and those that air at a rate of one episode per week are more likely to feature the entire cast in each episode, and to represent all current storylines in each episode. Evening soap operas and serials that run for only part of the year tend to bring things to a dramatic end-of-season cliffhanger.
In 1976, Time magazine described American daytime television as "TV's richest market", noting the loyalty of the soap opera fan base and the expansion of several half-hour series into hour-long broadcasts in order to maximize ad revenues. The article explained that at that time, many prime time series lost money, while daytime serials earned profits several times more than their production costs. The issue's cover notably featured its first daytime soap stars, Bill Hayes and Susan Seaforth Hayes of Days of Our Lives, a married couple whose onscreen and real-life romance was widely covered by both the soap opera magazines and the mainstream press at large.
The first serial considered to be a "soap opera" was Painted Dreams, which debuted on October 20, 1930 on Chicago radio station WGN. Early radio series such as Painted Dreams were broadcast in weekday daytime slots, usually five days a week. Most of the listeners would be housewives. Thus, the shows were aimed at and consumed by a predominantly female audience. The first nationally broadcast radio soap opera was Clara, Lu, and Em, which aired on the NBC Blue Network at 10:30 p.m. Eastern Time on January 27, 1931.