There are many advantages. Which one is the most important and valuable for you depends on your current process and the environment you are operating in (e.g. legal environment).
Apart from the obvious paper-cost savings, diwoBlood enables you to fine-tune your process. The data related to the donations is of much better quality than with a paper-based process and is made available faster to the downstream production steps.
diwoBlood simply guides donors, doctors, and staff members. Since all answers and comments are entered digitally, it reduces significantly the error rate compared to the data gathered from scanned sheets of paper. The electronic availability of the data can also be utilized to further improve your process. Knowing for example, how long the average donor takes to go through the single steps of the donation process can help you find and reduce the potential bottlenecks.
In addition, the replacement of the paper-based questionnaire and consent gives you increased flexibility towards changes, often triggered by regulatory bodies.