Don’t listen to my reasons alone. Listen to my past clients, who I mentored in growing their marketing agencies. And now they’ve grown their companies exponentially. Of course if you want to Google me you’ll find hundreds more success stories and reviews.
One of my clients gave the following testimonial in a video we recorded:

"It’s hard to believe that less than 2 years ago, I was working by myself in the spare room of my house and really struggling. Now we have great offices and great staff around us helping us grow exponentially.”
Kim Barrett
Your Social Voice

Not convinced? Understandable. You don’t want to waste your time on a whole book. 
Here is another testimonial from a marketer I helped grow their agency:

"We were certainly undervaluing some of the services we did. We used to do just a flat fee, $500/month. Looking back this was a terrible idea & I have no idea how I even came up with that [Now we charge much more than that]"
Charley Valher
Investor and Business Mogul