I was watching one of those, "The Making of..." special features a while back, and was surprised to learn about how casting selected their actors... This was for one of the Hobbit movies.
Anywho... yeah, they had to be great actors, but... they also had to be nice.
Nice?
Nice... friendly... pleasant to be around... whatever.
Apparently, they realized this might sound a bit odd, because they went on to explain... "We have to be around these people ALL THE TIME...", or something to that effect.
The thing of it is... you're not going to be stuck on some remote island or country months on end with your clients, so unlike the cast of The Lord of the Rings, or whatever... you don't have to be nice... or friendly... or whatever...
BUT YOU DO HAVE TO KNOW WHAT YOU'RE DOING.
AND YOU DO HAVE TO BE PROFESSIONAL.
The thing of it is...
Although you don't have to be nice or friendly... you do have to be able to look nice &/or friendly.
Marketing's a #####.
I highly recommend becoming very adept at taking screenshots of yourself.
It's a lot easier to capture the lighter side of your personality during a video, than having to give the camera something right there and then.
Refer to the following video for more information: