There's been some questions raised in the past about just how reliable the traffic and user stats thrown around by plenty of web sites are, and as ad dollars have flowed online, there's a growing interest among marketers in verifying those stats. Besides sites having good reasons to inflate their figures, there are other issues: for instance, there are plenty of different ways to count traffic (such as unique visitors vs. page views), and different stats packages often report very different numbers. Even the third-party measurement services that many companies use can't agree on traffic levels, so the Interactive Advertising Bureau is asking comScore and Nielsen/NetRatings to submit to outside audits of their services and methods, so publishers have a more transparent view of how the companies count their audience. The IAB's president notes that the companies have resisted calls for such an audit since 1999, so he understands he's facing an uphill battle. But with publishers wanting more transparency so they can be assured their audience isn't being undercounted, and publishers demanding more transparency to be sure that audience isn't overcounted, it's likely that something will have to give. The amount of money flowing into online advertising makes it a certainty that better and more accurate traffic stats will emerge, whether from comScore and Nielsen/NetRatings, or other, more willing providers -- particularly since a number of large advertisers have set a deadline of 2008 for sites on which they buy ads to have their ad impressions audited by a third party.