Web Publishers Start to Feel Lack of Advertising
Shakeout of World Wide Web publishers has been gathering momentum for at least year as Internet advertising has failed to grow quickly enough and users continue to balk at paying for much on-line material; battle seems to be evolving into war of attrition, with those with least resolve or resources dropping out first; some media giants, including Time Warner Inc, continue to lose heavily on Web ventures while awaiting medium's success (M)