The big American broadcast television networks just finished their presentations to media buyers, offering a preview of this September’s schedules as a means of selling as much advance advertising as possible. It used to be that Canadian networks looked at those schedules, figured out which shows to buy, sold their choices to Canadian media-buying firms and hoped their bets were right. Not any more.

‍     An increasingly fickle audience, instantaneous, metered ratings and greater risk aversion mean the television scheduling grid changes week to week. Shows are launched in January, June or any time their originating networks feel makes the most sense. American cable networks started the trend, launching new series such as The Sopranos or Sex and the City when the main networks were in reruns and viewers were restless.

‍     As a result, the TV season now runs a full 52 weeks a year — not just in a flurry every fall, although that remains the primary focus for the networks. Programmers have to think more like air-traffic controllers, constantly shifting shows in their schedule, replacing underperformers and counter-programming against the competition.

‍     “Part of what’s driving this is also escalating production costs,” says Bruce Claassen, chief executive officer of Genesis Media, a media planning and buying firm. “A first-run series used to be 30 episodes. Then that went down to 26, then 23 or 24. Now you’re seeing 20. They repeat shows in January and February because they know tuning [in] is high anyway, or they’re slotting in new shows then. They’ll take six episodes and schedule [the show] during the spring as a test.”

‍     Even a show that’s done well in the first part of the season may suddenly find something like The Osbournes or The Sopranos suddenly siphoning its audience away.

‍     Mr. Claassen says the changes in the TV landscape mean media buyers have to function like investment advisers, monitoring a portfolio of buys with respect to each client’s advertising objectives, changing and rebalancing the placement and cost of advertising to ensure the best return on investment. “The media world has exploded. This is just adding another layer of constant change and complexity to the situation, which means you just have to dance that much quicker.”

‍     Networks used to rely on ratings gathered during sweeps periods to figure out where the audiences were. Viewers kept diaries on their television choices from three weeks out of a seven-week window in the fall and four weeks in the spring. That produced a snapshot, but it was only a snapshot.

‍     With the advent of ratings meters, there’s a more complete picture of viewing habits. Nielsen Media Research introduced the people meter to Canada in 1989. “Everything is captured — a pilot, specials, awards shows,” Nielsen president Mike Leahy says. “So now, broadcasters aren’t guessing. It gives them the tools to make better decisions; it’s allowed them to examine the possibilities in other parts of the year.”

‍     That’s allowed News Corp. Ltd.’s Fox Network, for example, to reap numerous rewards by launching some of its new shows at different times of the year. Initially, that strategy had a lot to do with fox owning the rights to the Major League Baseball playoffs. The network unveiled shows it deemed promising in June or October — before or after the playoffs — as part of a commitment to year-round development.

‍     Beverly Hills 90210 first appeared in October, 1990. Melrose Place made its debut July 8, 1992. Launching programs at times other than September has helped make Fox number one among viewers in the prized 18-to-49-year-old demographic.

‍     That kind of year-round thinking has spread as the number of networks — broadcast and cable — has increased, and the advent of reality programs has accelerated program turnover.

‍     “We’re aware very quickly and can act to get a replacement or change from the broadcaster,” says Hugh Dow, president and CEO of media firm M2 Universal. “Instead of being in the dark and waiting for the sweeps, we’re informed constantly.”

‍     “Now we have six networks in the United States, and they’re launching programs all year long,” says CanWest Global Communications Corp.’s programming boss, Doug Hoover. Dragnet, he says, is an example of a successful non-fall launch. He attributes the success at least partly to the fact it was launched when much of the rest of the dial was in reruns.

‍     What happens in U.S. broadcast schedules affects Canadian viewing options because Canadian broadcasters aim to run American shows at the same time as they air on U.S. networks. Simulcasting automatically boosts ratings, and it’s the only way Canadian networks can ensure they’re getting their money’s worth out of U.S. programming. But competition between American networks means Canadian broadcasters sometimes find shows they rely on suddenly cancelled and supplanted by a show they’ve never seen. That’s made them bolder about shifting their schedules.

‍     “We’re always responding to changes,” says Susanne Boyce, president of programming for CTV. “That’s what led us to buy The Sopranos, to take The West Wing out of simulcast and put in Amazing Race instead.” The West Wing’s audience had proven itself loyal enough to follow the program.

‍     “Advertisers very much like simulcast, as do we,” Ms. Boyce says. “But we’re looking for opportunities. We haven’t seen negative impact on revenue because of shuffling, which is great. There was hesitation, but then it did very well.”

‍     “It’s meant that we have to refine our systems and ways of conducting business,” CanWest Global’s Mr. Hoover agrees. “Overall, though, I think it’s great for the industry. Commercial television has gotten a real shot in the arm” with the 52-week season. Broadcasters are more adventurous, looking for a wider range of shows.

‍     Or, as CTV’s Ms. Boyce puts it, “It’s great to have Lloyd Robertson, Ozzy Osbourne and Tony Soprano on the same channel.”