I examine how contactless tap-to-pay (TTP) adoption affects consumer spending using item-level transaction data from U.S. convenience stores. Exploiting staggered store rollouts within a triple-difference framework, I show that TTP raises monthly spending primarily by increasing transaction frequency; a phenomenon of consumption fragmentation. Crucially, while monthly totals rise, individual TTP transactions are smaller and contain fewer items. These effects are concentrated in impulse-sensitive categories like beverages, tobacco, and food service products. My findings suggest that reducing interface-level micro-frictions lowers payment salience and weakens self-control, demonstrating that even incremental fintech innovations fundamentally reshape the timing and composition of consumption.