Your Page must acknowledge that the promotion is not sponsored, endorsed, administered by or associated with Facebook

There are several third-party providers that help brands run Facebook promotions legally, and most have free trials. A few prominent ones are Wildfire, Offerpop and Buddy Media.

Complete Brand Page guidelines for promotions can be found here.

4. Overposting

Less is more. Facebook suggests that brands start out with one or two posts a week to feel out the platform and see what works. Many brands post once per day, and many find that posting more than once per day can actually have an adverse effect on engagement. Facebook indicates that the averages user "likes" four to six new Pages each month, so your content is constantly fighting for more attention from its fans. It's better to post one excellent item per day instead of two decent ones.

Even if you're only posting a few days per week, you can still keep your Page active on a daily basis. Check your Page and "like" or respond to comments on your Brand Page, and remember to tag the people you're replying to — that's a great and easy way to get people to come back to your Page to engage more. And it can be easily done with the new Facebook Brand Page Manager app. (Facebook says tagging features are in the works for a later version of the mobile app.)

5. Focusing Too Much on Likes

Sure, Likes are important — the more Likes you have, the more people your message is reaching. But Likes are just step one. Step two is to confirm that you're reaching the right audience and keeping them engaged, says Diana. If they "like," comment and share your content in a regular basis, then they have become brand advocates who are pushing your message to their friends.

The post above, from the Book of Mormon Facebook Page, shows solid engagement on all counts — Likes, comments and shares — thanks to a quirky photo and a clear call to action.

It's also important to note that content shares better on certain days — Buddy Media research has found that engagement rates for Facebook posts are 18% higher on Thursday and Fridays. So if you're strategic, you can get more engagement with fewer posts. Using the new posting tools, you can queue up the content you want to share throughout the week and then ride the wave of engagement over the next few days. "Brands that aren't paying attention to their own data and when their fans are engaged will not see the reach and engagement they desire," says Lazerow. Last year, Buddy Media released a more granular study of industry-specific engagement stats, indicating what days and times of day are best for certain kinds of content, which also can be useful for planning your editorial calendar.

6. Too Much Text

Facebook research has shown that posts between 100 and 250 characters — one or two lines of text — get 60% more Likes, comments and shares than ones that are more than 250 characters, says Diana. Buddy Media research found a similar trend, determining that posts with 80 characters or less in length have 27% higher engagement rates. The moral? Like content on Twitter, keep it short and sweet. Of course, your post should be different than your content on Twitter, or else your fans don't have a reason to follow you on both platforms.

One tip for making sure the post is as engaging and short as possible is to remove the link URL from the text field in the post. Once you paste the URL in the field, the page title, a blurb and a thumbnail will populate — you can then delete the URL to streamline the post and cut the clutter (see above).

7. Posting Boring or Off-Brand Content

This might come as a surprise (well, we hope not), but the things you post on Facebook should be relevant to your brand. If you own a company that makes iPhone cases, it doesn't make sense for you to post about a Kickstarter project just because you think it's cool. Being on-brand is a significant predictor of engagement — just because people like your product doesn't mean they share all of your interests, so just give them a mix of content related to the product. Since your fans don't see every single thing you post, you risk wasting their eyeballs on irrelevance and incurring negative engagement on the post.

8. Ignoring Insights

Facebook Insights offer a lot of useful information — it'd be silly to not take advantage of the data. The Friends of Fans metric is particularly interesting, as Friends of Fans typically represent a much larger set of consumers than a brand's Fans. In fact, for the top 1,000 brands on Facebook, the Friends of Fans number is 81 times larger than the fan count, says Bruich. This means there's a huge potential audience that can be tapped into by posting engaging content (because your fans' activity will show up in friends' feeds) and by enhancing this content with other Facebook ad tools, such as Promoted Posts.

Smith says consumers are 51% more likely to buy something if they know their friends did, so capitalize on the army of advocates who have opted in to learning more about your brand.

You should also pay attention to the People Talking About This (PTAT) and reach metrics in Insights to see how your message is faring in the Facebook ecosystem, and create a comprehensive Facebook marketing strategy based off of what works. "That's the kind of media plan that's going to lead to results," says Bruich. In a sense, you can think of your Facebook audience as a focus group and get a grip on what they want to see more of.

Also check out the real-time insights, which help you see the impact of pinning, highlighting and promoting posts.

9. Being Vanilla

While Timeline transformed Facebook into a much more image-based platform, it's important to spice up your content. Too much of anything is boring, and the right mix of polls, questions, photos and video will keep people engaged and excited about your brand. Humans crave diversity, and different kinds of posts drive different kinds of engagement — so a smattering will lead to more well rounded engagement. For example, someone might comment on a question post, share a photo and "like" a video, so it's best to give consumers a wide swath of ways to engage with your brand.

Pro tip: Asking questions is typically a driver of additional comments. The post above by Coffee Bean is a great example of engagement — it's an image that promotes a live Q&A session on the brand's Facebook Page.

If your brand is experimenting with video, Diana has an interesting finding to keep in mind — videos shared from third-party sites (YouTube, Vimeo) generate less organic activity than videos hosted on Facebook.

Regardless of what type of post you're sharing, make sure the tone and voice reflects the personality of your brand. Virgin America is cheeky, Birchbox is feminine and chatty, MTV is casual and approachable. What's your brand's voice? A Facebook user should know it's your content in their feed without seeing your brand name next to it.

10. Not Making the Most of Facebook's Ad Options

Not all businesses have the budget to employ Facebook Ads in their marketing arsenal. But brands that do could benefit from Bruich's advice about what makes a good ad.

He says the ad needs to be well branded. If it's not clear and obvious who and what the ad is promoting, then consumers will be less likely to recall the ad and the brand. It's also important to have some sort of reward or "payoff," as ads with a reward tend to be more influential over purchasing decisions. Also, try to have the creative in the ad have one focal point — with everything else happening on Facebook, a focused creative unit helps fans recall ads.

Can't figure out what your ad should be? Dig into Facebook Insights and turn the most engaging content into a social ad. "Your content and ads are one and the same," says Lazerow.

You can give your recent content an added boost with Promoted Posts, which extend the reach of your post and are easy to do. Sweet Cheeks Diaper Company, a brick-and-mortar and online store in Maine, saw a 49x return (tracked via the unique URL) after promoting a photo on its Brand Page, says Diana.

Conclusion

Facebook marketing is a crucial way to build a fan base and spread word about your business. But a successful campaign doesn't have to be a drain on your time or your wallet. A few minutes a day and a strategic plan can have an immense impact on your brand's Facebook presence, as long as you avoid the mistakes above.

If you're a newbie to Facebook marketing, you can check out a Facebook webinar at facebook.com/classroom. If you're more experienced and have a specific question about your Facebook campaign, Facebook encourages you to call 1-800-916-1300. For more information on Facebook Brand Page management, you can go straight to Facebook.