In January 2010, I interviewed with BCG for an internship position. I was still in that awkward case preparation phase where you know what you're "supposed" to say but not where you're comfortable to say "screw the formulas" and just approach the case with your own methodology.
My first case was the definition of awkward case student trying to follow the right procedures. I distinctly remember asking the question "can you tell me a little bit more about the competitive landscape for our client?" (If you don't know why this is a bad question to ask, look at the bottom of this post) as well as "Are there any barriers to exit?" (Without really knowing what that meant). I eventually stumbled my way to a passable answer, but it was overall a weak performance. In my second case, I wiped my mind clean of Case in Point and just approached the case in a way that made sense to me, and that went a lot better.
I didn't make it to the final round, and unsurprisingly, the feedback I got was that my approach to the first case was too forced and 'pre-packaged'. Still, I was still intent on re-interviewing for a final-round interview, and I knew that for full-time I was going to have to fight for one of ~8 first-round interviews.
In July (as I was hitting the case books hard), I reached out to both of my internship interviewers to ask if we could have a quick chat about consulting and BCG. Two weeks passed and I didn't hear back from either - I sent a follow-up e-mail to my second interviewer, which I was comfortable doing because we had connected well during the interview. Still, another week passed with no response and I was getting anxious. Finally, a week later I heard back from one and then two days later, the other. We talked about the interview preparation process, my interest in consulting, and their work experiences. Before I sent in my applications for September, I sent e-mails to both to thank them once again for their time and to let them know that I had applied and was looking forward to hearing back from BCG.
I can't say for certain whether that made a difference in my application, but I later heard that I had been put on a list of 'students with potential', was invited to a dinner with a partner and a couple of consultants, and ultimately did get the first-round interview....