[...]But beneath the surface, another figure marked a seminal moment for Dulles-based America Online Inc., the media company's Internet unit: The number of U.S. subscribers fell for the first time ever on a quarterly basis, dropping by 170,000 in the last three months of 2002. The dip occurred despite the aggressive launch last fall of the company's newest software, AOL 8.0; the distribution of millions of free AOL computer disks; and the outlay of more than $1 billion on advertising and promotion during the year."The modest decline in AOL's subscriber base will spark renewed fears over AOL's long-term viability," investment...