A Harris Interactive poll of 2,309 US computer users found that YouTube's most frequent users didn't like the idea of having to view advertisements in order to access the service. 31% of frequent users said they would use YouTube a lot less if the Google-owned company pursued plans to show brief video advertisements before allowing access to content, while another 42% said their viewing would drop off a little. Just 21% said it would make no difference.

"Consumers as a rule are not averse to watching commercials online in order to catch an episode of a TV show they would otherwise miss," Harris Interactive research manager Aongus Burke said in a statement announcing the results. "Yet those who are accustomed to finding and watching everything for free at YouTube may have developed a very different set of expectations for the site."

According to the survey, 42% of adults using the Internet had viewed a video on YouTube, and 14% of those classified themselves as frequent users. Predictably, usage spiked amongst younger viewers, with 75% of males aged 18-24 having used YouTube.

Of the frequent user group, 32% said that they were watching less television as a result of the service, and 36% said they were visiting other Web sites less frequently.

Earlier this week, YouTube said it was working on a system that would allow content creators to share in ad revenues from viewing of their videos on the site. Such an approach will only be effective if YouTube can block the placement of copyrighted material, an area where it is also planning to introduce new technologies.