All writers should consider having their written work proofread and, if necessary, edited by professional proofreaders. When a writer utilizes professional proofreading services, he or she is taking the extra step in terms of making sure that the final document is free of errors and intelligible.
The goal of professional proofreaders is to eliminate errors, clarify the writing, and ensure that the thesis of the document is clearly and interestingly presented so that it will be understood by all who read it. If the point of writing is to convey thoughts and information, then the document itself must be clearly and correctly written. Professional proofreaders ensure that all documents on which they work are just that.