Marcelo Prince writes: "... The audience [for Internet radio] has reached "a critical mass" and "advertisers are starting to take an interest in it," said Andy Lipset, managing partner of Ronning Lipset Radio, a New York ad agency that sells ads for several big Internet radio stations. ¶ But efforts to attract advertisers to the nascent market have been hampered by a debate over how individual stations -- everyone from small broadcasters like WOXY.com to giants like Yahoo Inc.'s Launchcast -- should measure their online audiences. There is no agreed-upon method. Instead there are dueling systems that can produce different stats. ...¶... The software counts users by monitoring the number of Internet protocol, or IP, addresses that are connected. There are some limitations: Most home users have a single IP address, but one address might be shared among hundreds of office users. Mr. Mendell said because of that and other factors, Ando Media's numbers tend to undercount a broadcaster's audience by about 5%. While the system does not provide demographic data, Mr. Mendell said an Internet radio station could conduct a separate survey to get such information. ..." Link: Wall Street Journal.