A panel on "word of mouse" at the Bandwidth conference focused on new trends in social networking and how advertisers can leverage those networks to reach music fans.

Aaron Barnes, VP of sales and business development at Friendster, pointed to the growth of widgets as a hallmark of web 2.0, and said that ad penetration can be partially measured by branded widget development and use. He acknowledged that there is still no perfect way to target an audience, but social networks help brands get close.

David Rosenheim, CEO of Jambase, added that he is still seeing most promo dollars going to radio and print, but the ratio is changing over time. He pointed out that many social networks can also utilize geographical targeting, which entices many advertisers to sign up.

Barnes added that advertisers want to use social networks for niche targeting, but that there is a fine balance between targeting and being too niche. He also stated that most users know they are being targeted, and brands have to be sensitive to that.

The two-day music and technology conference wraps Friday (Aug. 15).