I have been lurking and occasionally posting on this and other sites for a number of years. One thing that never ceases to amaze me is how many people claim English as their primary language and yet have no idea what it is supposed to look like when written! Occasional typographical errors don’t bother me, but habitual misspelling of words, incorrect use of punctuation, or just using the wrong word in a particular situation drives me up the wall. It’s not just on website forums and pages, either. I see it on an almost daily basis in documents and letters written by people who are supposed to be professionals. I have seen better writing from people whose primary language is something other than English. From my perspective, incorrect use of the language only undermines the credibility of the writer. Interestingly enough, someone else must think this way, too, because they have put this page up on wikipedia:
http://www.wikihow.com/Use-English-Punctuation-Correctly
Language is a tool to be used, and to be used most effectively, it must be used properly.