Here is how it works. First, you make sure your personal Facebook page is at least reasonably attractive as a promotional page. Yes, it's your personal page and not your fan page - but Facebook only allows posts to groups from "people." So you want your profile photo and your top banner to both present well to strangers. You don't have to market your book(s) with those areas but at least have them reasonably professional looking.
I personally do allow people to friend me and I keep my deeply "personal" posts off that personal page. I prefer fans fan my author page, but any contact is better than zero contact. The more I can build my fan base, the more books I can sell.
So now that your personal Facebook page is set, you next want to join as many author-promoting groups as humanly possible. What I do is set up a spreadsheet with them all. That way when it's time to do a promotion I just click-click-click my way down those rows and paste my promotion into each group. It takes maybe 2 minutes top to hit 50 different groups. Quick, easy, and powerful.
Here is an example of my spreadsheet:
Facebook Group Promotion Spreadsheet - ZIP file last updated 09/28/2015
So each time I run a promotion I make a new column with the date of the promotion and the book I promoted. That way I can keep track of when I did what. I aim for no more than once a week for a given book. You don't want to keep hammering a list - that would be counter-productive and get you banned. Once a week is a good balance.
Note that each group has its own requirements. Make sure you respect those so you aren't banned.
Once you're approved for those lists you have to optimize your promotional blurb. It has to be short, meaningful, and eye-catching. This is not the time for long-winded essays. Aim for 2-3 sentences with punch that get your message across to lure in the reader. It has to be powerful and quick. So like:
FREE Clean, heartfelt romance in the lighthearted style of The Bachelorette. The men are strong, rugged, and handsome. Who will she trust with her heart? http://www.amazon.com/Knowing-Yourself-A-Medieval-Romance-ebook/dp/B006JDEK0I/ Please share!
You always want to encourage shares. Shares are the key to a wide reach.
Make sure you're making a post at least once a week!
Note about your timeline: By default the setting in groups is that your timeline gets filled with group-related news. For these marketing groups it could easily mean your entire timeline gets peppered with update after update of people posting to the groups. I highly recommend when you join a group (or when you make your first post) that you turn notifications OFF. That option should be in the "..." menu immediately beneath the main group banner. That will help to preserve your sanity :).
In general this Facebook group spreadsheet works well for all authors in all genres. If you have seven different books and post a different one each day for a week, and then start the cycle again at the beginning of next week, that works perfectly. Authors do that all the time and nobody complains. Facebook is fine with that level of posting.
I know an author who had a book which featured male-on-male bondage scenes. He noted that in his description of the book. He started posting about his book and he was only about a third of the way through this list before his account became locked up. Enough people had complained about his book - that quickly!! - that his account was suspended. When he got it reinstated he couldn't post to groups or work with groups at ALL. He is still appealing that. So note that if you post material members find questionable that they might hit that "report" button - and if enough of them do that, automatic flags will trigger.
Those flags are in place to prevent a spammer from joining a bunch of groups and then flooding them with, let's say, child pornography or something. But what a given group member chooses to flag is completely at their own whim. So if your book is in any way "on the edge" where people might react poorly to it, even if the forum doesn't explicitly state rules about content, then go slowly and carefully. You might not want to risk your Facebook account over postings in these groups.
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