Electronic-commerce designers must already build sites that handle audiences with a wide range of technology available, balancing the needs of 28.8Kbit/sec, modems with T1 lines, for example, and version 2.0 browsers with more current ones.
Soon, site designers may face yet another technology split: computer monitors vs television screens.
For now, devices such as Microsoft's WebTV are a small percentage of the Inter-net audience. But IDC last month predicted that shipments of various TV-based Internet devices will soar from 1.4 million units this year to more than 11 million in 2000.
Those devices include not only WebTV, but also items such as cable and satellite set-top boxes that can deliver Internet data along with conventional TV programming. "This type of functionality is going to become a little more pervasive," said Kevin Hause, an analyst at IDC.
If and when TV emerges as a major factor in Web surfing, several site designers said some of those surfers may have to forgo aspects that depend on client-side computing, such as Java applets. That's already the case for those who use older browsers.
Because of differences in screen size, resolution, colour palettes and the like between televisions and computers, a Web site's appearance tends to change when viewed on a TV screen - and not always for the better. "It doesn't look as good on WebTV," said Cyndy Ainsworth, director of marketing at Virtual Vineyards, the wine and gourmet food site run by Net Contents. In addition, site strategies should change to attract users who are sitting on a couch across the room, said John Schmitz, vice president of design at Interactive Bureau in New York, a major Web design house.
"You're generally viewing it in a very different way," he said of TV-based Internet data. Although the computer user may read small type and scan for information, the TV surfer is more likely to be in an entertainment frame of mind - even when looking at a news or shopping site.
"You need to have much faster impressions of what you're seeing. It's going to have to look much more like advertising on television looks . . . Doing an online newspaper [or catalogue] is not going to cut it," Schmitz said. That means more pictures, larger type and fewer words.
Only a handful of sites are developing versions optimised for TV viewing because the current Internet TV audience is so small.
Tom Lix, president and CEO of Web design firm Newmarket Network, decided not to design the popular Car Talk site (for National Public Radio's syndicated auto advice show) for WebTV after the site's 1996 launch, when WebTV had sold about 100,000 units.
"It's hardly worth worrying about" right now, Lix said. "When it gets bigger, we will design for it." Web sites can be redesigned fast enough that he can afford to react to moves in market share and not try to predict them, he said.
In Europe, digital TV is "quickly emerging as a second interactive platform, competing with the Internet for consumer interactivity", according to a study released last week by Jupiter Communications at its Online Forum in London. Jupiter predicted that by 2002 digital TV interactive services will penetrate 19 per cent of British households, 12 per cent of French homes and 28 per cent of Swedish homes.