The NRS estimates reflect the potential audience for advertising within the print publication. The advertising in the print publication is different from that carried by the related website, so it is important to measure the print audience separately.
In the NRS readership questions, participants are asked (and reminded) to exclude any reading done online.
Between 2004 and 2008 NRS ran a test to monitor whether, despite these instructions, some participants did include online reading in their print readership claims. A dozen or so titles were included, chosen on the basis that they had websites with relatively large audiences.
The results of the test were encouraging. In some cases Average Issue Readers had read the publication on the Internet as well as in print, but the level of solus Internet readership was low.