You are the master of all you see as you enter your potential client's building; the same client that you are going to browbeat for twenty minutes into buying all of your inventory and at the end, he will thank you for your personal attention. You reach the ante-chamber to your client's office and who's that? Oh, it's nobody, just a receptionist. "Tell Mr. Client that I'm here to see him," you demand authoritatively. "Certainly," she replies and in you go.
What you might never know is that "nobody" is around your client all day, every day. Her opinion probably matters greatly. If the strength of your products or your pitch doesn't make the sale, then it will most likely come down to your character. If so, you'll probably lose. Also, the "nobody" controls scheduling for your client. That's right! Your next meeting got bumped. Do you need to leave a message? Guess who will be "writing" it down. Most receptionists will be professional and not stoop to petty vindictiveness, but there is no way to spot who is who. The next "nobody" could file your phone message in the trash.
Though receptionists are the mighty gatekeepers, they require nothing more than common courtesy and respect. The more they receive, the more they are prone to go above and beyond to help you. Remember how they are always around your client? Well, they will know his likes and dislikes, hit pet peeves, favorite colors, and his birthday. They might also know a lot about the business, its needs, your competitors, and where you stand in it all.
So be pleasant, understanding, respectful, and charming. You never know what the receptionist can do for you.