I'm in the same boat as you. This: And that got me thinking. Marketing on social media isn't really my thing. Does that mean I'm just doomed to failure in promoting my work because I won't get on board? Is it possible to do this without it?
There are loads and loads of channels you can use. Find the ones you like/enjoy. Remember, you just have to get very good at one. That's enough.
1) Really exceptional writing
2) Really exceptional packaging (book, title, selection of genres, keywords). My assumption is that blurb doesn't matter at all. I see authors who have an email signup link instead of blurb and I think they do better.
3) Having lots of books that inter-connect with each other. A little book network.
4) Email List
5) Understanding of free promotion sites/channels like word of mouth and free sites.
6) Understanding of paid promotion sites and a budget. Remember: This is optional. And in most cases the boost is temporary and will only have lasting impact if your work is very good.
7) Social Media. The people who are good at social media are SOCIAL by nature and talk about it A LOT. So it tends to get emphasized disproportionately.

Search Engines (Organic), keywords, Blogs, sites.
9) Giveaways and contests.
Of these, only the 1st is vitally important and some authors succeed even without that. So social media you can forget.
I personally know of several authors and other content creators who sell hundreds of thousands of copies without investing even 1 minute a day in social media.
You have to focus on your core competencies - the intersection of your passions and your natural aptitudes.
If it isn't social media - no problem. It isn't that powerful anyways. Everything you build is owned by someone else.
If instead you channel that energy into writing more books, writing your own books, building an email list, getting readers on your blog - those will be castles that you own.
FB now charges people money to show updates to their fans. Just yesterday they said they'll start pruning Likes based on 'regularity' or some nonsense. Remember, a lot of the social media sites are glorified ponzi schemes. They are most making money from authros and app develoipers and website owners and business owners who are desperate for traffic. They aren't like search engines where people are SEARCHING for content. People come to FB to chat and shoot the breeze. And FB throws in ads in between to try and make money.
While you could reach all your fans for free it was great. But now you have to pay to reach yoru own fans. If you're not good at it, it's a blessing in disguise. Imagine how it would feel if you built up 30,000 fans on Facebook and then FB says - if you want to reach all of them pay us $100 per update.
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also it's important to remember that it's only your strengths that'll make you successful.
If your true strength and passion lies in writing great books and cross-marketing them super well, then no amount of time spent on social media can get you success.
Social Media is a lure in some ways (unless you're very good at it). It takes up time and makes you feel you did something, when actually, unless it's your core competency it hasn't added much.
What you should do though is tie up your blog or site to FB and Twitter so automatic updates go out. And perhaps once a week check up and post some update.