Progress with Membean is nonlinear; at times you will see many new words, but at other times you will be consolidating what you have learned in your memory. The reinforcement is essential for learning the material well over the long term. Some study tips are here at Guidelines for Learning.
Membean's Adaptive Reinforcement Engine
The Membean Adaptive Reinforcement Engine determines when to introduce new words. One of the options that impacts the engine is the "Strict memory mode" in Your Preferences." This slows down the rate of new words. An individual student's personal training history is also key in determining when she or he will get a new word. In general, regular training is the key to making the best progress with Membean. Train for 15-minute sessions on alternate days (or 3 times per week), and you will see a good mix of new and review words. With regular training, you can learn between 300 to 400 words per school year, and master a significant percentage of them.