Kevin Rose, founder and chief architect of community content-ranking site Digg, shared his thoughts on how user-generated content can be monetized and used to engage consumers during this morning's ad:tech San Francisco keynote. Evan Hansen, editor-in-chief of Wired.com, interviewed the entrepreneur. Rose said that his site, which was largely founded to democratize content online, was now seeking to create a way for consumers to respond directly to advertisers about products and promotions.