As we all can see, the LOA's are given to the 'exceptional' candidates...probably the top 10 percent of an already ridiculously competitive group of applicants. Some are definitely also used for minorities and athletes. Getting everything in early is key, but if you don't have the goods, it aint gonna matter! My daughter was extremely competitive, went to SLS, has long family history of WP grads, and had her file done by September. But, no LOA because she wasn't quite as high SAT wise as most listed here, nor did she fit the minority/recruited athlete category. So, while it's very important to get your file done early, just in terms of getting early appointment, it will not help you get an LOA if you aren't one of the very top candidates to begin with.