Everything that requires a very important task to get done is to be taken seriously. The creation of a great logo is going to depend on your choice of designer. The factors to consider range from experience and cost, to the personality of the design and how well that person can work with the company that hires their service.
These are all factors that you need to keep in mind when you decide to hire a perfect logo designer for your needs. Ask yourself if this person has experience in your niche. This is probably the most important thing to consider.