A method for brokering a cloud service comprises receiving a request for a service and identifying parameters from the request. Further, a set of vendors who may satisfy the parameters of the requested service is identified. An invitation to respond based on the parameters is transmitted to the set of vendors. Responses including an estimation regarding the parameters are received from the vendors, and confidence levels that the vendors will meet the estimations are calculated based on an objective service history of the specific services. The responses and confidence levels are presented to the requester, and the service history is updated based on parameter results once the service has completed.