Hey there, I got them to sign up a few weeks in advance, in February actually. Many of them were getting the invalid token error, which is really annoying. I am afraid there are no other ways to get the students to sign up quickly for free. Even a few months later, some of my students are still yet to get their accounts approved. Thanks! Its good to see that I'm not alone in getting students on to Steemit! Hey, we may even get to do like an international Steemit student conference. Now that would be cool