This is interesting as I read somewhere that blogs are the thing to have on your website (or perhaps I was told by someone who writes blogs!) and I was panicking about having to include one on mine. Spelling and grammar are not my problem of course but time is and I am certainly not going to pay someone else to wax lyrical on my behalf!
As a proofreader I would agree with Steve and say that you don't want bad spelling etc on your main website as it undermines your credibility and professional edge, in my opinion.