The DART system applies a sophisticated, proprietary algorithm to adjust for the effect of invalid clicks on the count of clicks and click rates. Their analysis has shown that very few clicks that appear to be from real users are being discarded. DoubleClick considers a string of 10 requested clicks on one link, from the same user, within a 10-minute period, as invalid. To search a web site, a spider clicks on a link to access new pages and content. These programs cannot be prevented from accessing a web site in the same way as spiders or crawlers can.
Some web sites use tools to verify the links on a site.
To do this, the tool must click on a link to ensure that it is still valid. When a spider or crawler, a download program, or a link analyzer goes to a site, it generates one false click per page. Note that the effect of these three programs depends on the layout of the web site. So, sites with large volumes of pages are significantly effected, while sites with a few pages are not really effected. DoubleClick has and will continue to educate the marketplace on the reasons for these discrepancies, but Sportsline advertisers can rest assured that DART's numbers are reported using the highest industry standards.