The NYT has taken a special look at some practices by U.S. newspapers who deliver papers to non-subscribers because they are paid to do so by a sponsor.

They found that circulation drops would have been 10 times worse had circulation rules not allowed for those third-party programs.

An excerpt:

The unsolicited deliveries were made possible by rule changes the newspaper industry approved three years ago. The new rules allowed so-called third-party sales - which the industry once shunned - to be counted as part of a newspaper's total circulation. Without them, many newspapers would be losing circulation at a far higher rate. In the industry as a whole, circulation has been falling for a decade or more.

Maintaining the appearance of healthy circulation has been critical to newspapers at a time when the industry is losing advertisers to other media, like the Web and television. Because paid circulation determines in large part what publishers can charge for advertising - the lifeblood of an estimated $58 billion industry - any deep sustained losses threaten to erode the already shaken confidence of marketers and investors.

To determine just how much third-party sales contribute to newspaper circulation, The Times analyzed circulation data that 669 newspapers provided to the Audit Bureau of Circulations, a nonprofit oversight body operated by publishers and advertisers. To gauge circulation on the day when it is typically highest, The Times analyzed figures for Sundays, but also included weekday figures for two major papers that do not publish on the weekends - USA Today, which is owned by The Gannett Company, and The Wall Street Journal, owned by Dow Jones & Company.

The Times's analysis found that the combined average paid circulation for all those papers for the six- month period that ended March 2004 fell by fewer than 125,000 copies a day, or 0.2 percent, compared with the six-month reporting period that ended March 2002. But had third-party sales been excluded from those figures, as they were before 2001, the average paid circulation of those papers would have fallen 986,000, nearly 2 percent, over the two-year period, to 55,443,650. (The drop would have been even steeper had The Times's tally also excluded "newspaper in education" programs. Those programs seek to build readership among the young and are often paid for by third parties; for the most part, results in that category have long been counted under audit bureau rules.)