This year my school is really trying to boost our vocabulary test scores. I am trying to get teachers to use technology everyday in the classroom/homework. I plan to use this starting tomorrow in my classroom. We just recently purchased a new vocabulary textbook, and this will go so nicely. Also, an easy homework assignment will be for the students to add to their pages the new list. That in itself will help them study. If they never revisit the site to practice with, they still have typed it up.
I wish it was a little easier to add students to your group. It would be nice if they could just join without having to sign up. I wish I could send them a link and they could just log in with password to view their words. This way I could add words for them to view without inviting them every year.