In three separate introductory psychology classes over a three-year period, I tested whether over 600 students' exam scores were associated with the use of textbook technology supplements (TTSs). Each class used a different textbook and a different TTS ("Learnsmart," "PsychPortal," and "Aplia"). In general, students who used TTSs more, performed better on their exams (controlling for GPA). Additionally, higher scores on assignments on TTSs also correlated with higher scores (controlling for GPA). Students reported not having enough time or adequate motivation as the top reasons for why they did not use TTSs. I present suggestions for the use of such systems based on how I required the aids over the years.