I have been reading since I could sit up, literally. I started reading Wal-Mart bags upside-down in my great-grandmother's kitchen, nearly giving the poor lady a coronary.
Having simple errors on a business, or personal, website can be a major detractor and put off potential clients or destroy credibility. There is no substitute for a well written presence of any kind. If you're going to put yourself or your business out there in the public eye, look in the mirror and at least "comb your hair" because when people view your written content, they are interviewing you, seeing what you have to offer them. Make it beautiful by making sure it is right. I can help with that. I see things others miss, I always have.