It’s a foot in the door. A face with an application. Indicates you are willing to go above and beyond (even if it is just a time and money thing).

Depends on the company and which job fair whether or not there is any value or how much value there is. From what I understand AA did not even look at resumes at WIA. SWA was actually reviewing applications, going over them and helping people make changes that would improve the chance of their application getting pulled. Know several guys subsequently hired as a result.