Pop-up ads continue to gain momentum and drive up traffic numbers for little-known Web sites, according to a study released on Monday. Jupiter Media Metrix's September traffic figures indicate that online pharmacy network ABPharmacy.com ranked No. 33 among US Web properties, beating out sites such as iWon.com and LookSmart. The research company said the majority of visitors came to the site from pop-up ads, which pump up unique user counts by automatically opening a browser window linked to the site. ABPharmacy's climb follows a controversial pop-up ad strategy from camera maker X10, an approach that first landed the little-known company among the Internet's top five destinations in May. Some research companies say they don't see the value in including figures from such intrusive advertisements in traffic reports; others, including Jupiter Media Metrix, contend that including pop-ups produces more consistent results. "Pop-up ads actually have an increasing presence on the Web," with more people viewing information through such promotions, said Charles Buchwalter, vice president of media research at Jupiter Media Metrix. "We feel it's a legitimate way of tracking what people are doing on the Web." Buchwalter said that the results for ABPharmacy provide information about people's online behaviour, such as where Web surfers came from. He said the largest source of traffic to the pharmacy network came from Gay.com, Fastclick.net and FoxSports.com. However, rival measurement company Nielsen/NetRatings said many people click through pop-ups accidentally, and including such clicks in traffic counts could skew results. "We have deviated from Media Metrix's in our strategy with regards to pop-unders and pop-ups," said Tamara Gaffney, senior product manager at Nielsen/NetRatings. "The reason is because we don't believe that it accurately reflects where the user had intended to visit -- and further, it clearly changes the demographic profile of the site." ABPharmacy could not immediately be reached for comment. At the top of Jupiter Media Metrix's September rankings there were no shifts from the previous month's list. The company placed AOL Time Warner in the top spot with 81 million unique visitors, followed by Microsoft sites with 70 million, Yahoo! with 65.6 million and Terra Lycos with 38 million. X10 came in fifth place with 34.7 million. The research company also found that traffic to news sites skyrocketed as a result of last month's terrorist attacks on the World Trade Center and the Pentagon. Jupiter Media Metrix said 51 percent of Web surfers visited news sites in September, an increase of 40 percent from the previous month. CNN.com hit the top news spot with 24.8 million unique visitors, an increase of 141 percent from the previous month. Each viewer spent an average of 33 minutes on the site in September, up from nearly 24 minutes in August. MSNBC.com came in second in the news category with 22.2 million unique visitors, followed by Time.com with 9.5 million, ABC News with 8.99 million, NYTimes.com with 8.96 million, and WashingtonPost.com with 6.8 million. See the Internet News Section for full coverage. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Telecoms forum. Let the editors know what you think in the Mailroom. And read other letters.