Big Bucks: $1.5 trillion--that's the size the business-to-business e-commerce marketplace is expected to hit by 2004, according to investment bankers Goldman, Sachs & Co. At press time the company expected revenues for 1999 to hit $114 billion. . .Size Matters: How big is the Web? There are currently 3.6 million Web sites, with close to 300 million publicly accessible pages, says the Online Computer Library Center. A quirky factoid: Only 42,000 sites are pornographic (so why do they send out so much e-mail?).