Nope. Not if it is done right.
Check out this cool blog by my sales presentation expert pal, Steve Mertz. http://www.salespresentationtraining.blogspot.com/
This is good stuff… if you need some help with your sales presentations… you should check out this training resource.
Speaker, Trainer, Presentation Skills Expert, Lover of AppleJacks Cereal
(I do some presentation training too… look here.)