Like others have written, you pay a large subscription fee and then you only get 30 unlocks. The kicker is that you don't know if what you're unlocking is what you need, complete, or even has the correct answers. So you use those 30 unlocks in about two weeks and then they want to you to pay $15 for another five, which gets you maybe one more assignment. It didn't used to be this way, I've used them in the past. I'll never use them again. Basically I paid $75 for two weeks worth of help on three assignments.