If you're serious about being an author, you carefully comb your books for mistakes before you publish them. You agonize over word choices, think deeply about plots and get incredibly picky when it comes time to design and choose a cover design. You pay attention to all the little details when you're presenting your book. But don't think for even one moment that you can slack off in the way you present yourself. In fact, it's something you've got to think about constantly.
Being a Brand
Once you label yourself as an author and start presenting yourself on the Internet through a blog, social media profiles, forums or any other venue, you're no longer a person. Now, you're a brand. You've got to start acting like it.
Awhile back, I did a post reminding you that you're always an author, even when you're kicking back for some Twitter time. Whenever you're using your author name in any public way, whether on a forum post or even in an email to another author, you need to be thinking about how you're presenting yourself.
Presentation is Everything
Specifically, I'm talking about all the typos. The grammatical errors, and the lazy punctuation. If you can't send me an error-free query letter, why would I review you books? If I'm reading your post in the forum asking me to buy your book and you're totally ignoring all rules of period usage, I'm going to have a knee-jerk Grammar Warden response. I know it to be true, because I've heard myself say out loud, on more than one occasion, "if you can't capitalize your Is, I can't read your book."
And I'm really not all that choosy about what I read. I read books across all genres of all lengths based on all sorts of plots, so I'm pretty open-minded. But your average reader? They need a lot more wooing than I do, and they may write you off even more quickly than I.
Everything you put out there is ultimately associated with your books and your writing in general. So if all I see from you is sloppy Facebook updates and forum posts that ignore everything about capitalization and commas, what do I think about your books? That's right: I'm going to think they're sloppily-written, too. It might not be true. It probably isn't true.
The thing is, I'm not even going to try to find out. That's why you have to think about personal presentation, because I'm certainly not the only reader who feels this way. You are being judged, unpleasant as that may be. So present yourself well, and you will end up selling more books.