To enhance the empirical knowledge of commercial cargo bike utilization, 755 companies and public institutions throughout Germany tested cargo bikes in operational use for a duration of three months. This article provides a characterization of the users, their experiences and evaluation of the vehicle type and addresses its use and environmental impact. Three waves of online surveys were conducted over three years, and around 30,000 vehicle trips were recorded. The organizations showed considerable heterogeneity in terms of size, economic sector, and location. The study identified environmental protection and taking a pioneering role as the main motivations for participation. Cargo bikes were used more frequently for services than for deliveries, with an average of 2.8 days per week and 12 km per day of use. The general suitability of cargo bikes was positively assessed, but potential product improvement was seen, e.g., with regard to the handling of the cargo box. About one third of the participants decided to buy their own cargo bike after the test phase. The study suggests that policy measures such as purchase incentives during the market ramp-up period and improvements to bicycle infrastructure, should be taken, while the industry should improve the reliability of vehicle components and offer better maintenance services to customers.