Why do I need a proofreader?

Once you've written your copy, it's hard for you to notice any errors in your writing - your brain sees what you meant to write, often not what's on the page.  Having a fresh pair of eyes look over your work can save you the embarrassment of sending out thousands of business cards with the wrong phone number, or missing out on a job because of a few typos on your application letter.

Do I need a proofread or do I need copy editing?

If you're happy that what you have written is clear and concise, then a proofread is all you need.  A final check of spelling, grammar and accuracy.  
If you're not entirely happy with your content, then a copy edit might be wise.  I can ensure that your text is as crisp and concise as possible, as well as checking the spelling, grammar and accuracy.