A loaded question... hehe
A year ago, I had my own business, specializing in
SEO and Design. I received a referral from a former employer and managed their Search Engine Marketing. I was doing okay, nothing crazy but for a home business 60,000 a year creating results for 1 client and multiple others in design work, it wasn't bad either...
Today, my personal clients are worth close to 500,000 in annual (billable) business for multiple forms of online marketing including SEM, online software and design.
I am currently a partner in a web design and marketing company in Las Vegas, my SEM clients are in constant communication with me, they view me as their marketing consultant. I am constantly looking at ways to increase their business online as well as create a better website and user interactivity without compromising their current rankings. Their business is my first concern... I am monitoring visitors, rankings as well as results on a regular business. You could stop me on the street and I will tell you exactly how any of my clients are doing online.
I never guarantee rankings, I guarantee results. I feel that anyone who "guarantees ranking" are just looking out for themselves and not their client. I receive constant referrals for SEM and other work from our current clients. My name, my business is their first thought when their business partners are looking for our services. I have clients that say my name constantly to their business partners, it's contagious and our phones ring...
My advice to anyone in this business is... Create results for your clients and in return you will create a partnership that leads you to more partners. Create results for yourself alone and expect to be alone.