Apples aren't oranges nor is a stream an episode.
That's why the Web video world, mired in confusion over how to count viewers on the Web, has begun to move toward a common ground.
NBC stirred up a hornet's nest in June when it announced it had delivered more than 300 million streams of video on nbc.com since last October.
The result? More confusion, but also the first steps toward a standard.
The Internet Advertising Bureau is putting together a team to develop guidelines for counting Web video audiences, said Sheryl Draizen, senior vice president and general manager with the group.
The dispute over how to count audiences on the Internet - by streams, episodes or show starts - is heating up as more people watch TV programs online and advertisers try to figure out how much they should be spending to reach those viewers.
At stake is a big new business. Advertising in streaming video should hit $1.31 billion this year, up 39 percent from last year, according to a June research report from Accustream iMedia Research.
Most networks break up online episodes into four to five streams for a drama and two to three streams for a sitcom, making it easier technologically to deliver the shows and also to insert ads in each "commercial break." But those benefits carry with them the potential for manipulation when it comes to counting viewers.
Following NBC's news, Turner Broadcasting said it intends to report how many episodes of its TNT and TBS series are watched online, rather than how many streams, or segments, of a show get played. Earlier this year, Turner reported that TBS "My Boys" had delivered 2.7 million streams online. But each episode was broken down into three streams, providing an unclear picture of how many episodes consumers were watching.
"I want to give more information rather than less and at least give information they can compare to other networks or to episodes on our Web sites," says Jack Wakshlag, chief research officer for Turner Broadcasting.
So far, there is little common ground. ABC reports episode starts and NBC reports streams, which gives the network a sense of volume. Fox releases aggregated streaming figures for Fox Interactive Media, which includes Fox's full-length episodes and MySpace videos as well. CBS has not reported its online video consumption.
The IAB expects to issue guidelines within the next 12 months or sooner.
The need for accurate measurement extends to viral video. Advertisers, marketers and video creators are eager to know how their videos fare across video-sharing sites such as YouTube, MySpace, FunnyOrDie.com and others. Vidmeter.com posts a dynamic list of the most popular videos across the Web. The parent company Vidmetrix also offers a detailed and custom analysis of a video's performance for marketers and media companies, so they don't have to visit each site and add up views manually.
Vidmetrix faces competition from other firms such as TubeMogul and Quantcast, which in July began measuring video views on individual sites and across the Web, reporting reach, plays, category and amount consumed.
Both TubeMogul and Quantcast are free to use, but are exploring revenue models.