Using a theory of affordances, this study examines the introduction of e-books into the early literacy environment as resources that can increase children's opportunity for learning vocabulary. Added value was observed under conditions of (1) book browsing, (2) instruction, and (3) a print-only condition. A total of 33 4-year-olds (18 boys, 15 girls) from nine Head Start classrooms assigned to one of the three conditions participated over an 8-week period. Mean differences in target words learned in total and by mode in each condition were statistically significant in favor of the e-book-enriched environments. Differences in word learning between e-book environment conditions were clinically significant. Mean differences in words learned by total and by mode for children with varying levels of vocabulary knowledge (low, average, high) showed that those in e-book-enriched classrooms learned about 25% of the target words with children with low vocabulary showing comparable gains. Results suggest added value of e-books in the early literacy environment: (1) affording children more exposure to target words to their advantage, (2) creating a choice of reading material in the early literacy environment, and (3) providing built-in scaffolds (e.g., hotspots) that may carry some of the teaching load of vocabulary instruction.