The Blood Service is stunned by the "amazing support" for its Missing Type campaign, in which more than 2000 people signed up to become first-time blood donors in 10 days.
The response to the campaign was "overwhelming", says the organisation, which has produced a video in which recipients of blood products say thank you for the life-saving support shown through the response to Missing Type.
The Herald took part in the campaign that involved dropping Os and As from online branding, logos and social media accounts to draw attention to the need for O-type and A-type blood donors.
The campaign ran in 21 countries. In New Zealand it focused on A and O blood types because they are in the most demand here.
The service's national manager of marketing and communications, Asuka Burge, said she knew the campaign would be powerful, but even she was not prepared for the nationwide reaction.