I also got a $15 credit just for signing up today, so again, it sounds like a win-win. If you're thinking of signing up I think they're only giving $15 vouchers until the start of April. They want to build a following before launching, I suppose.
The sign up process was just a matter of entering my Email address and first name, then clicking the verification link when they sent an Email, so it was certainly easy enough; no surveys or personal information asked.
If you sign up for Educents here it is a referral link for me; I'll get an extra $1 credit. You'll get a referral code if you sign up too if you want to post on your own blog or Facebook. What do you think? Worth a try?