Google is testing new ad placements on a number of its websites, it has emerged.The search engine has already started experimenting with new ads on YouTube and Google Image Search and is to extend the trial to Google Finance and Google News.According to a post on the Official Google Blog, Google Finance will see tests involving text ads, with the possibility of display ads appearing on the site in the future.Meanwhile, ads on Google News will be trialled in the near future. Nick Fox, director of business product management for Google stressed that the new placements will only come into force if they uphold the search engine's principles regarding usefulness and relevance."Of course, these experiments benefit Google because they generate revenue from new sources - but by ensuring that we show the right ads at the right time to the right people, we'll add value for users too," he said.According to New Media Age, marketers are wary of how useful the new YouTube ad placements will be. Rob Proctor of technology firm Reality Digital told the website that there is "still a nervousness" about online video among advertisers, despite the fact that user-generated content is becoming more popular among consumers.