I would pay more attention to the quantity of dashboards a company creates than just the number. It is important to determine your business objectives and what data sources you are using, as well as who will be reading your reports, before you hire a data visualization service provider. Inquire about their experience with your preferred visualization tools and if they are able to do data cleaning or integration if necessary. Security is another important consideration, particularly if dealing with confidential business data. Examples of past projects are also helpful. If you have an additional data need, but also require a team that can link visualization to it, then Datalance is something worth looking into.