What do you like best?
My favorite part about Shmoop is the humor weaved throughout the website. I think this humor helps keep the student more engaged, particularly through some of the lengthier lessons. Shmoop includes content on a variety of subjects and tests, at a variety of grade levels.
In addition to Shmoops great subject specific and test-prep tutorials, there are some great tools like the Essay Lab and Flashcard Builder that are built-in.
What do you dislike?
While I am appreciative of the free content offered on Shmoop, the free version is loaded with advertisements. The free version is also plastered with "Sign up for our premium package". Unfortunately, some of the things that appear to be accessible via the free version turn out to be premium content, but the user will only learn that after multiple clicks through the beginning of the module or guide.
Recommendations to others considering the product
Shmoop has a lot of great content, but only a small portion of it is available on the free version. I would strongly recommended browsing through the content before subscribing to ensure that what you're looking for isn't already available for free.
What business problems are you solving with the product? What benefits have you realized?
Textbooks often offer one or two practice tests per unit and sometimes that isn't enough for the student. Shmoop gives students access to additional tutorials and practice quizzes with feedback. This has been great for our students needed extra practice without putting extra work on the hands of the teacher.