Grammar-Nazi: Read no further!
Sure grammar is important in any copy and there is about zero point of arguing with that fact. But that, in fact, never means you are actually writing a textbook or an essay for your English teacher. You are to maintain Zen, a balance between grammar and a conversational tone for your copy to be great.
Sure you may be quite the grammar-Nazi and your text may be richer that a tale by Dickins but will such a post or ad look appropriate to most users? Won’t it look arrogant and cocky? It, by all the ouds, may look so indeed. And, apparently that was not in your original plan, right? You have the power to make your writing meaningful and worth a lot to your users by bending a rule here and changing a word there. After all, your message has to be clear and understandable!
Don’t get carried away, though!
You are into SEO services with your copy, aren’t you? And that is work in the first place rather than mere entertainment. As mentioned before the trick is in balance. If your copy will simply be overfilled with typos and errors it will lose any trust and business value. After all, who might wish to have business with a person whose IQ and skills equal the same of a third-grader?
A proper word to a proper man!
Make sure you are using appropriate words when writing your copy. Words that are close to your target audience. And if an ad is for teenager all hell may break loose with your creativeness and even any fictional word like ‘world’s best awesome-o-major-top-ice-cream-pudding thingy’ may do the trick. And the same approach will not work if you are writing a copy for a serious company with customers even more serious.
Simply consider this. You are telling the very same news to your boss in a different language than you will be telling it to your family members, right? Especially if the news causes you to feel emotions, right? Same with copy and grammar alongside with it. Be clear with your message and deliver it to just the right people and you have 90% of a successful ad covered.