HBS is not really going to give you any brownie points for visiting and going the extra mile to demonstrate interest will also likely not get you anywhere with them. They know everyone wants to go there and few turn it down (some do, but HBS has a high yield). What they are doing at this point, is seeing how the final round goes, and will pull from the waitlist only to balance yield numbers from previous rounds and to compare you against R3 applicants. The only thing you can really do that would be valuable would be to submit information that indicates some kind of material change in your profile--for example, if you got a promotion at work or some kind of community award, etc. Basically anything which was not available to include when the application was due. Make sure you don't make the mistake of adding something you feel would be interesting or important, but which could have been included in your application when it was due. Communicating with the admissions committee once you are on the waitlist should only be for three purposes 1) to give them new information which is material to your admission consideration 2) to reiterate your interest to remain in consideration for admission or 3) to withdraw yourself from consideration for admission. So at the very least, you should send a message to the admissions office thanking them for keeping you on the waitlist and reiterating it's your top choice school and you would accept immediately if offered admission. Believe it or not, telling them you would accept has some (albeit small) value, since it helps them navigate their yield numbers (but again, they are not often worried about yield as i mentioned before). As for being a reapplicant, in general there is a higher acceptance rate among reapplicants, but this is somewhat of a self-fulfilling prophesy since people generally only reapply when they have truly increased the value of their application. In other words, the higher acceptance rate likely comes from the simple fact that the applicants have added significant achievements to their profiles--otherwise, they generally know better than to reapply. If you are able to not only log more work experience, but do so with some impressive accolade or achievement in leadership skill or some other salient attribute for b-schools, the short answer is yes, you could have a better shot as a reapplicant.
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Bryant Michaels
Admissions Consultant