MixerCast launched on Tuesday in public alpha. The very sleek site is designed to allow anyone to take content from their desktops and across the Internet and mash them up to create their own visual collages of sorts. But here is a twist. Users can get paid for their work by choosing which advertisements they want displayed on their creations. While mash-ups aren't new, certainly, mashing up advertisements advances this whole notion of taking control of the viewing experience. Leading the startup is Jennifer Cooper, who ran Yahoo Platinum and oversaw Yahoo Broadband, and has apparently mashed up her experiences with Adarbad Master, an engineer who created the service, after receiving $2.6 million from ComVentures back in December 2005. Cooper came on board 90 days ago to help build a company from Master's technology. At this point, the 28-person team is seeking a B round of funding in the $5-$7 million range. MixerCast is as its name implies. Just as DJs mix music, MixerCast allows people to mix content to create their own broadcasts. Cooper showed me her little news broadcast she created with content from ABC News, one of MixerCast's content partners. All told, MixerCast has half a dozen partnerships with media properties, including National Geographic and Getty Images. The business model is mainly advertising. In the case of ABC News, MixerCast will get 30% to 40% of ad revenue for views generated on its site. MixerCast will also try to get media companies to sponsor templates, such as ABC News has done. MixerCast will also try to get companies to place products in the templates. Other sources of sales include affiliate marketing, in which MixerCast gets referral fees from Amazon.com or Apple's iTunes for any customers it sends to those outlets.