Novi and Troy are Detroit suburbs that are accessible from the freeways, have lots of hotels and are convenient to shopping, restaurants, etc. Very easy places for touring girls to stay and for clients who see girls in your price range to access.
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I have seen a few touring girls advertise that they are staying at the casino, but I don't think the casino scene in Detroit is connected with hobbying in the way it is in, say, Vegas. For the most part, people coming to gamble at the casino are not potential clients for you.  
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Downtown Detroit is really coming back and worth checking out, but the vast majority of your potential clients are out in the suburbs.