I would stay away from any advertisments, e.g., BP and the like, that show exceptionally model-like women in the NW suburbs, incall only, NO OUTCALLS - emphasize NO OUTCALLS. Pay special attention to the geographic location...Near Woodfield mall, Schaumburg area...general vicinities. Also, stay away from western suburb locations that specify Itasca, Addison or Bensenville. In addition, in the NW suburbs, if an ad has, again, a smoking hot girl in the pics, stating that she as well as her friend could join you...stay away. Another key clue is the area code of the phone number - be wary of the 630's and 331's. If you do, in fact, get to the point of calling one of these providers, and she greets you with and finishes every statement with "baby" or some other cheesy term of endearment, again, be wary.The aforementioned are all rip-offs. Typically, these locales are spas; however, some are rented apartments or houses that rotate teams of girls that operate under the same spa-like MO.
Now, this is not to say that all providers in the NW suburbs are rip-offs. Just pay attention to the details of the ads.
I learned my lesson a long time ago as a newbie hobbyist. As they say, never grocery shop on an empty stomach. The same may be said for seeking out a potential nighttime friend - think with the head on your shoulders, not in the pants; read the fine print...if it seems vague - red flag. If it seems too good to be true, it is.