Not a good sign

It looks like this proofreading service could use a proofreading service.

I know some people are thinking that the semicolon should be a colon, but it shouldn't.  It just simply should not be there.  This is a basic punctuation error, and what makes it hilarious is that you would think a copy editing company would actually use their copy editors for their online advertisements. 

Or maybe they were just hoping that their potential clients are so uninformed in the ways of grammar that they wouldn't notice.  Either way it's sad.

Or funny.  You choose.