This longitudinal field experiment compares two different for-profit market entry strategies with a philanthropic strategy in terms of how each influences consumer behavior in Base-of-the-Pyramid (BoP) communities. We analyze reactions to a water purification product offered at three price points (moderate discount, deep discount, and free) in rural Malawi. We find that those who paid the deeply discounted price remain more likely to re-obtain and use the product than do those who paid the moderate price or who took it for free.