Writing is not a solo sport. As much as we would like to crawl into our writer's cave and hibernate in there until our book is complete, that just isn't possible or a good idea. Trust me I'd love more than anything to hide in my introverted self. Writer plus engineer does not equal extrovert, but I've forced myself to step outside my comfort zone and its been to my benefit in many ways.
It takes an army....
... to publish a book. There's typically an agent, editors and many others that are involved in the process. But it also takes an army to write a book. You can't do it 100% alone. Even if you can find the motivation, time, and drive to complete a book start to finish on your own, you can't be a one writer show. You need feedback and lots of it. As writers we are too close to our work and its impossible to single handedly catch every mistake, pov change, awkward phrase, pattern, abused word, etc. The list goes on an on. Not to mention, you personally can't find the points that don't make sense or need more detail by yourself. You don't know how others will view the story and you need that input. To get that kind of feedback you need to interact with others.
The power of critique partners/groups
I've already discussed why you should have critique partners and get feedback, but there is a lot of other things a group of critiquers can do for you. First on the give aspect, I've learned a wealth of things just by critiquing others. In seeing things that other writers need to improve upon, I often am able to notice similar faults in myself and correct them. The more I critique the more my writing improves because of it. And that is just the tip of the iceberg.
Not only do critique partners help me tighten up my writing but they provide me with a drive to keep going. There is nothing like an angry critique group waving their flaming pitch forks at you asking for more to you story to keep you writing. Okay maybe I exaggerated a bit about the flaming pitch forks but having someone say they love your story and they can't wait to read more is great motivation to keep you writing. If you aren't extroverted enough to go find a critique partner or group you are missing out. Not to mention they are great sounding boards for working through writer's block, plot issues and the general stuck in the process feeling. They are a great shoulder to "cry" on because they've been there too, they get it. In addition, there has been many occasions where I've helped other writers work through trouble spots and its sparked an idea for myself, or helped me realize a change required in my own manuscript.
This is something that I'm new to, but if I hadn't stepped out of my introverted box I never would have tried it. In meeting other writers, I've made some new friends. And there are times where we all say to each other, I need to write. So what better motivation than to group up at a coffee shop or library and write together. In most cases write ins were not times I normally would have been writing but because I knew other people were expecting me to show up, I came and got stuff done. It's also great for sticky points. There are times when you are writing and you get stuck on some wording or plot point and have to stop. But if you are writing in a room full of writers you have the potential for a quick instant brainstorming session. In the short time I've spent doing write ins I've already increased my productivity because I'm being held accountable for my work and I'm scheduling in time, that I may not have typically planned.
Twitter is a huge wonderful resource for writers. I know some people roll their eyes, and I used to be one of them, but there is a great writing community on Twitter. There are writers, authors, agents, publishers, and editors all out there sharing great publishing (#pubtip), editing (#editortips) and writing tips(#writetip, #writingtips), as well as keeping you up to date on the latest trends and happenings. And its all free! There is also a whole slew of writing contests you can find via twitter where you can win critiques, edits or even possibly get signed by an agent. However if you hide behind your word document you are losing out to all of this. Not to mention there are great hash tags such as #askagent where real agents will answer your questions.
Long and short of it, don't be afraid to interact with with these hash tags or even the people behind the accounts. They are people too, they don't bite and you'll find a lot of them share similar interests as you. Do however be professional. Don't twitter pitch to them unless there's a specific contest or they ask for it, and do not spam, either your stream, anyone's account or the hash tags. Doing these things will put you on a crazy insane bad list that you don't want to be on. You will find the more you interact, the more resources you will find, the more fun you will have, the more you will learn, and if all that wasn't great enough, you'll find you are starting to build your brand as a writer. If you are being respectful and sharing good insight and things you like, you will find that you will start to gather a following. Whether published or not, its great to have this kind of reach. None of which would be possible if you didn't embrace your extroverted side.
So there's a few great reasons to step out of your box and be an extrovert. What are somethings you do to be more outgoing that have in turn have benefited your craft? I find that the more extroverted I become in the writing realm the more my skill improves and the more work I get done. So don't be afraid to step outside your comfort zone. Get out there and get to know your fellow writers.