La Croix-Rouge de Belgique (the Francophone Belgian Red Cross) needs to maintain a sufficient stock of blood all year round to meet the needs of hospitals. Among the most valuable profiles are donors with O-negative and B-negative blood types. So what’s the problem? Even though most Belgians know their blood type, there are still too few Rhesus-negative donors. Therefore, a campaign was needed to mobilise Rhesus-negative blood donors to donate before summer, while also recruiting new donors.