The two biggest reasons for unhappy clients are delays in getting the project done, and a design which the client doesn't like. The second can lead to the first since you might end up having to redo a design several times.
Marketing companies have several ways of dealing with this. One is to offer the client several "looks" at the start to choose from, hoping one will hit a home run. Another is to charge the client extra if it takes more than a certain number of tries or revisions before the client will sign off on it.
I had another idea. It's actually one of the things that separates us from most design firms.
I took problems in getting the client to sign off on a look, as an indictment of the development process. As a result, we've worked hard to refine the development process to make it as efficient as possible. We found, for example, that a conference call or meeting with the client and our designer was essential. That way, the designer had an opportunity to get a feel for what the client was looking for, straight from the horse's mouth.
Studying articles on marketing by L. Ron Hubbard, I found flaws in our design sequence. There is a natural sequence of development that if not followed can cause you to have to backup and redo steps, or end up with something the client spits at. We straightened it out.
The net result was a design development process that is relatively rapid and efficient, and almost sure to develop a "look" that is going to please the client, first time. Typically, there are some adjustments needed. It is rare for us to have to start over.
As a consequence we can offer as many versions or revisions of the look as necessary, at no extra charge.
Clients like that.