I see too many students making the mistake of spending all their time on the booth at the expo. Since the companies are already searching the database of the students already registered, it is important for you to upload your resumes.
In case you didn't know, many companies are conducting onsite interviews in separate rooms while some of the company representatives are working at the booths. Also, seriously consider joining the event at the student full conference level, which will give you the full access to the entire conference program, minus the gala dinner. That's where you can make personal connections with recruiters and executives at the companies.
Let me know if you have any questions. I have been organizing these types of events for over 12 years now.