eMarketer posted a great recap of the Virtual Worlds Conference, in which online gaming executives talked about their industry, growth trends in the online gamer audience, and the mixed experiences of advertisers who have set up shop in virtual worlds like Second Life.

Robin Harper is senior vice president of Linden Lab, the San Francisco company behind Second Life. She told eMarketer that some disappointments in the virtual advertising space could be chocked up to a "Build It and They Will Come" mentality.

"Like any other campaign, you have to consider what your objectives are," said Ms. Harper. "Building a virtual store and then not staffing it properly will leave customers disappointed."

eMarketer's piece also shares survey results from a Deloitte/Harrison study. Headed "Types of Online Ads that Influence Users," the list is topped by search engine text ads top the list. Ads in "Web 2.0" media like online games and online videos bring up the rear. Unsurprisingly, oung "Millenials" and "Gen Xers" surveyed a little higher on the impact of ads in virtual worlds , they still corresponded with the overall totals.

• Search Engine Ads: 78%
• Interactive ads incorporated into information or entertainment: 62%
• Banner Ads: 60%
• Video Pre-roll Ads: 31%
• Video Post-Roll Ads: 19%
• Embedded Video Ads: 17%
• Ads or Product-placement in Online Virtual Worlds: 17%
• Ads  or Product-placement in Online Video Games: 15%