Chicago—Hammered by the decline in traditional ad revenue, b-to-b magazines saw their operating margin plunge, on average, from 11.0% in 1999 to 0.6% in 2003, according to a new profitability report prepared for American Business Media by The Jordan, Edmiston Group Inc. The media investment bank presented its findings Monday at ABM's annual Top Management Meeting in Chicago. During the five-year period covered by the report, the average b-to-b magazine's ad revenue fell from $3.4 million to $2.8 million, and its EBITDA (earnings before interest, taxes, depreciation and amortization) plummeted from $505,000 to $24,000. Richard Mead, managing director of Jordan, Edmiston, stressed that the profitability study didn't cover alternative revenue streams, such as trade shows, conferences, newsletters and the Internet. He said Jordan, Edmiston would try to include that information in its next study for the ABM. The report was based on a survey of 111 magazines: 98 with less than $5 million in annual revenue; nine with revenue of $5 million to $10 million; and four with revenue of more than $10 million.