E-commerce sales tough to qualify.(forecasts for electronic commerce sales)(Brief Article)

Amount varies wildly depending on researcher

In the next few years, e-commerce sales will explode, soar, zoom, boom, skyrocket, climb to dizzying heights, hit whopping proportions and break through the stratosphere. That's an old assertion. The big question is by how much.

International Data Corp. says worldwide business-to-business sales will reach $2.23 trillion in 2004. Forrester Research predicts $6.3 trillion, and Gartner estimates $7.9 trillion. Jupiter Communications matches Forrester at $6.3 trillion, but it's projecting for the U.S. market only. What gives?

HARD TO MEASURE

"The funny thing about the Internet is it defies …