Discretion is important, do you (or the provider) want to be seen meeting in the lobby?  Sometimes it is unavoidable like when you need key card to use elevators. A single person passing through the lobby is easier to overlook then a woman meeting someone who has been standing there for 10 minutes.  But a hotel with a bar or lounge could be a much better place to wait.  If your really going for the GFE then how about meeting around the corner at a restaurant or coffee house? Some may even consider that "off the clock".