In its blog, the admissions committee at Harvard addressed the question whether it is worthwhile for applicants to apply in the third round, considered to have lower chances for acceptance. Here are some main points:

“You may be surprised to learn that we ask ourselves the same question every year. Should there even be a round 3? Why can’t we just wrap the class up in two rounds? Answer: even though we could – we always conclude that we like Round 3 enough to keep it as an option. Although we have admitted about 90% of the class by this time, we always – ALWAYS – see enough interesting Round 3 applicants to want to do it again. I know you wish I could define “interesting” with pinpoint accuracy but I can’t…

Maybe it would be helpful to turn the tables and give some advice on when it’s NOT a good idea to apply in Round 3. So…
DON’T apply to HBS in Round 3 if:
• You are an international candidate and have serious concerns about the likelihood of getting a visa in a timely manner.
(We’ve seen this happen and it may cause you serious stress and uncertainty about whether you will be able to get here in time for term start-up.)
• You are expecting an Admit Welcome Weekend to enable you to meet future classmates.
(We don’t have one.)
• You really want to come in September, 2012 and are hoping to be granted a postponement.
(Won’t happen.)
• You are counting on getting on-campus housing.
(You’ll have missed the lottery. On campus housing COULD work out for you, but you may need to find other options.)
• You are using this as a “trial” application and are hoping for feedback on this application to increase your chances of success next year. (Can’t do it.)”

Put Me in Business (applying in less than a year)
Put Me in Business (applying in more than a year)