1- Agree with others on paying students to write reviews.
2- You need to improve your UI significantly IMO. From your home page it seems that you would prefer users to register before using/contributing to the site, which I think is not a good idea. Your homepage should be immediately useful to the potential users/contributors. for examples you should have a searchbox(with auto-complete feature for the name of universities and courses at least). Or list of most actively discussed courses, etc.
This is in fact an unsolved problem. Current database systems cannot handle this level of connectivity. Facebook can't do a "push" because of all the features they support. It gets extremely complicated if they push complex data into user's mailbox. And twitter cannot do "pull" so they can avoid putting a cap on the number friends/followers but then that's why they cannot really add any feature.
Wal-Mart is the Wal-Mart of the web. Their online holidays' sale numbers are higher than Amazon.
edit: http://siteanalytics.compete.com/walmart.com+amazon.com
well this shows Amazon gets 20M more traffic than Wal-Mart during peak of holiday season, but I am pretty sure Wal-Mart's sales were higher on 06