There is a common question in everyone's mind " Does GRAMMAR & Spelling mistake matters in ranking?"
According to me these are the most important factors, because all websites are been made with a focus of selling something. Selling here includes services,income from Adv.,goods,etc. So, even if you are ranking high through PPC it will only increase the bounce rate of your site. Because the only factor which works after a visitor enters your site is the content of the site. And if there are grammar / spelling mistake in your content, it will spoil the reputation of your site and end up with high bounce rate. But as an Internet Marketing Consultant if I would only concentrate on ranking I would say it hardly makes some difference.
But personally I would always suggest you to concentrate on these factors not only while your are writing the content for your website, but also consider it while posting something on your blog / facebook / twitter.
And as always I have added a video of Shree Matt Cutts talking about the same topic.
A solely owned blog of RK Iyer with an intention to represent my thoughts & experience