From what I understand, for app store optimization, the title is very important. Selecting the right primary category is also important, but apparently the secondary category is not as important. Including the category in the title is not necessarily important unless that category word is something people would use to search to find the app. Keywords also play a role. Including any terms that people would use to search will increase the rankings. Keywords should be singular (they finally handle most plurals) and you don't need spaces in between keywords. In my case, keywords might be: liquor,beer,wine,drink,food
However, my recent experience with Happy Hour strongly implies that Title, Category & Keyword mostly impact search results. If that still results in a large number of apps, the ranking inside that list seems to depend most on the total number of downloads and "velocity" of downloads, where velocity is the number of downloads in a period of time. So, it seems a bit like putting the cart before the horse, but the way to appear at the top of the list is to get more downloads, and to get them in a shorter period of time. I would suppose that also implies that traditional marketing or a strong burst of a social networking campaign to drive traffic and volume could be an effective tool to increase the ranking.
Cheers!
--tom
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