I had recently completed an internship in the same field just before applying to UPS as a soon-to-be graduate. I do believe I flubbed one question, but answered it to the best of my ability considering it was out of my undergraduate studies. It was an hour-long interview that I felt went very well. I sent a writing sample to the interviewer, and I felt as if I performed admirably. I received a courteous response to my sample email, and that was the end of communications. I feel like if a potential employer is going to devote the effort/time to interview with your company in-person, the minimum effort on the company's part is to send a "thanks but no thanks" offer via phone or email. It's kind of bad manners to not even send a notice.