Yieldex, a startup that helps online publishers forecast ad inventory, has won the Amazon Web Services Startup Challenge, netting $100,000 in cash and services. Yieldex built its ad forecasting platform using the Amazon Elastic Compute Cloud and the Amazon Simple Storage Service. It won $50,000 in AWS services as well as $50,000 in cash, and may even get an Amazon investment. In addition, it and six other finalists got to pitch their businesses to several VC firm including BlueRun Ventures, CMEA Ventures, Greylock Partners, Hummer Winblad Venture Partners and Madrona Venture Group, who help judge the contest. Last year’s winner Ooyala managed to score $8.5 million in venture funding two months after it won. But those were different times.