A better question to ask would be why are you working 2 hours of strolling for 100 people if that doesn't fit your act? After all YOU are supposed to be the pro and know what should be appropriate for your client In that circumstance. Many times my client wants to overbook me... Say for example booking me for Five hours of strolling magic for a group of 150 people. I would never do that and I would recommend what is appropriate for them. Explain that in your experience It's always best to "leave them wanting more" ... and not to become an annoying pest. Remember you as the professionals are there to help guide their decision and make a successful event for them. Most people booking you probably don't book a lot of entertainment so you want to help guide their buying decisions to what is best for them.

Now in the event that they are expecting 150 guests and only 75 show up, Then it is your responsibility as the entertainer to adjust your show accordingly. You work longer for those who want to see you ... you may have to work less for those who are Not particularly interested in you. I feel that you should be skilled enough as an entertainer (note that I'm not saying as a magician ... but as an ENTERTAINER) that you should be able to entertain a group of party guests In the limited times that you would experience a less than ideal performing situation

All the best,
Jason Christopher