[anilr]

Did you have face-time with the companies before the on campus interviews?

Companies I've worked for in the past have hired far less than 50% of the people they brought in for interviews. It's like a blind date, you know a little about the person, but there's still a lot of missing information so not getting the job is the norm, not the exception.

That said, asking for feedback on what you could improve might provide you with insight. Also, review your resumé, do you think the companies expected a competency you don't yet have?

Head-up, there are lots of big companies out there. Some, like Google, still have a lot of choice in hire, while others (Yahoo comes to mind) can't be quite as picky! :)