The recruiters you will be meeting with at a job fair are seldom the actual Hiring Managers. They are usually Human Resources (HR) recruiters who make their living as professional screeners. Their job is to weed out the undesirables so that Hiring Managers can spend quality time with the candidates who are on target for their needs.
However, some employers will have a Hiring Manager attend along with the HR Recruiter. This is especially true for smaller to medium-sized employers.
You need to have a different focus for HR Recruiters than you would for Hiring Managers. Recruiters are typically looking to screen you out, not qualify you in. Your objective should be to show that not only do you have all the necessary basic requirements, you are also an appropriate candidate for their work environment. Consider their focus. Whenever they make a recommendation for further action, they are putting their stamp of approval on the person. The last thing they want is for the Hiring Manager to come back to them and say, "Why did you give your recommendation for that person?" They want assurance that company resources will not be wasted in taking the next step with you. Ideally, they should be able to visualize you as someone who could eventually become part of the team.
Although recruiter styles vary, you can usually get a good feel for a Recruiter at a job fair by two very observable features:
Is the above always the case? Obviously not. These are general observations made over the years from many job fairs. However, you will find about an 80 percent positive correlation (meaning that it's wrong a solid 20 percent of the time) in the observations above. Another observation is that fully 90 percent of government recruiters sit behind the table with no smile. Definitely weird. It's like they are all cast from the same mold. Must be government regulation at its strangest.
If you want to sell stuff for a living, job fairs are job search nirvana. Retail sales. Insurance sales. Financial services sales. Manufacturing sales. If you want sales, you will definitely find it here. For the rest of you, job fairs might drive you crazy. Why so many sales jobs? Because most people who are in sales are not in sales by design. People don't typically go to college with the intent of becoming an insurance salesperson. At the same time, these companies rely on an efficient sales force to generate a profit. Most of them like to grow their own, so entry level is often ideal. These companies are out there beating the bushes at the job fairs. Quite often you will see a top-tier company on the list of employers recruiting at the job fair, yet arrive to find they are only looking for marketing reps (i.e., sales reps).
But here is the key: even if companies are actively recruiting only for sales, if the line is not too long (and you have the time), approach them to inquire about whom to contact for a position in your field within the company. They might offer instead to take your resume and get back to you (you will likely never hear from them again), in which case you should request their business card for direct follow-up. Then call directly at a later date to find out the name and title of the primary contact within the company who is responsible for hiring in your line of work.
Don't let the "Sales Reps Only Need Apply" sign turn you away from an employer you are truly interested in!