Are you acting as a Commercial Air Tour Operator? Whether you are or not doesn't matter. The FAA may think you are.
See the great article by Greg Reigel attached at the end of this FAQ for more information on this subject.
"How Do You Know If You Are A Commercial Air Tour Operator?" by Greg Reigel
Midwest Flyer Magazine
August/September 2013, page 10
ATTACHMENTS ------------->>>>>>> : MFM-AugSept2013.pdf