There are many ladies, including myself, who offer MSOG. However, I choose not to advertise that, because listed it seems like a guarantee - and if the hour is up and the second, or third, shot hasn't happened, it's quite difficult to gently remind the gentlemen that our time is up.
For me, if I can please a man multiple times in one session that's fantastic - but, if the gentlemen chooses this, he needs to be mindful of the clock. I am not a clockwatcher in any way, however I have had the experience where someone is so determined to get the second shot in that we've gone well over the paid time, and when I remind him, I look bad. I've spoken with other ladies too who have had the same experience.