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About 28% of blood is collected from first‐time donors, about half of whom return within the first year [27]. Those who return tend to be white, US born, and college educated [28]. Experience with the first donation has a major effect on their willingness to return for subsequent donations [4, 14, 16]. Although the first blood donation is anxiety producing, it is usually accompanied by good interactions with the donor staff and good feelings about the donation and oneself [28]. Thus, most donors realize that they are reasonably able to give and plan to do so again. With continued donation, the experience becomes easier and the reasons for continuing to donate become more “internal” [3]. Ferguson et al. [29] propose that the “warm glow” associated with donating supports a general benevolence hypothesis.

About 70–80% of donors are repeat donors, although this percentage is decreasing [16, 30]. Repeat donors tend to be 16 and 17 years or older than 50 years, male, Rh negative, type O, without a reaction during donation, and have a college degree [16, 31]. A shorter interval between the first two donations also predicts more continued donations [28]. Over time a “blood donor role” develops in repeat donors, and this strengthens self‐commitment to blood donation, including “friendships contingent on donating, a self‐description as a regular donor, an increase in the ranking of the blood donor role, greater expectations from others, and even more donations” [4].

Donors who are deferred are less likely to return to donate after the reason for the temporary deferral has passed [4, 16]. This is not surprising because deferral breaks the good feelings that might have developed about donation and makes future donation more difficult. Experiencing a reaction also reduces the likelihood of a donor returning [4, 14, 15]. This is because the donor begins to see himself or herself as someone who has trouble donating, and the reaction experience modifies any previous positive feelings about donation. Surprisingly, most multigallon donors report that they do not receive recognition for their donation, and the knowledge that a friend or relative was a blood donor did not make them more likely to donate [9]. These observations are consistent with the general view that the initial donation is motivated primarily by external factors and continued donation primarily by internal factors [32].

A disconnect exists between blood supply shortages and demographic reports that there are actually more eligible blood donors in the United States [33]. Simply put, it should be easier to meet the blood unit demands of the US medical system. However, experiences have shown that 12 million units in 2017 were donated by 9 million donors, representing 4.8% of the of the population eligible to donate. For many reasons, from demographics to logistics, many potential donors do not present to donate [33].

Donors are also more time conscious and desire a shorter (or more efficient) donor experience. Long wait times and screening may deter some from many blood drives. Blood collectors are looking at more self‐directed donor screening and additional software changes to decrease donor wait times.

Perhaps the most contentious area affecting continued donation may be iron depletion of blood donors. This is a widely debated area, with some medical directors arguing for more stringent monitoring of donor iron loss and others suggesting that we maintain the status quo. A review by Zalpuri et al. [34] addresses existing literature from 12 studies, regarding whole blood donors and health consequences from iron deficiency. The authors did note a high prevalence of iron deficiency among whole blood donors. The studies were much more conflicting as to what symptoms or conclusions could be drawn.

One confounding factor was that there is a lack of universally representative iron parameters for iron deficiency. Another confounding issue is that replenishment of hemoglobin and ferritin levels across the population of whole blood donors is widely varied, making comparisons between studies difficult. Ultimately, the effect of blood donation and subsequent iron deficiency (or transient deficiency) on overall quality of life could not be found [34].