5% of Ireland’s population are O negative, yet it accounts for 16% of demand. This means O neg donors are often contacted to donate, risking donor fatigue. To mitigate this, Give Blood paused to thank its O neg donors. 18,733 donors received a deliberately simple letter. When opened, the envelope window visually shows the impact of their donation. Inside, a note with O in every word represents the universal importance of O negative. Crucially, the piece doesn’t request further donations, instead trusting the power of a thanks to bolster the intrinsic motive that drives people to donate blood.