Sheryl Sandberg, Google's vice-president of global online sales, deflected questions about Google's display advertising effort and whether it has gotten off to a slow start - saying Google is still in the testing phase - writes Reuters. "I think it's fair to say we have basically just started," she is quoted as saying in response to a question from analyst Safa Rashtchy at the Piper Jaffray Global Internet Summit in Laguna Beach, California.

Google rival Yahoo continues to dominate online display advertising, whereas Google's revenue is dependent on pay-per-click, text-based search advertising - but over the past year it has been experimenting with inserting small image-based ads into search results, and plans to offer "click to play" video advertising as well.

Rashtchy also asked about Google's ad plans to cover "all media" and what that might include; Sandberg replied, "Our long-run vision is that we will be working with advertisers…in lots of formats," but declined to specify which.