Same here. I'll often buy a substandard book from the "21 days" or "24 Hours" series, even with all their lack of editing and inferior writing, over other books

Same here. I'll often buy a substandard book from the "21 days" or "24 Hours" series, even with all their lack of editing and inferior writing, over other books. Why? Because the exercises they usually have help me retain more that a better book.