A sales pitch filled with spelling and/or grammatical errors is probably the single most unprofessional thing a salesman can do, aside from hitting on a potential client's wife or daughter.
First impressions are critical in sales, and this first impression screams: "I have no idea how to write English properly, and I'm too stupid or poor to hire a fluent English-speaking person to proofread my pitch before I send it to the world. On a sidenote: please buy my lights."
Just my $.02, bro.
Best of luck to you in the other 400 forums in which you probably have already posted....