Make no mistake: A Facebook fan page can be a powerful marketing tool for small and midsize businesses.

But recent controversy over the organic reach of small businesses' Facebook posts has brought scrutiny to the social network's push to get small businesses to engage in small doses of advertising. Those little doses are called Promoted Posts.

They let owners of pages with more than 400 fans pay as little as $1 to promote any post created during the previous three days. Paying to promote the post means it will be shown in the news feed of more of your fans than you would normally reach, and friends of your fans are also more likely to see the post.

There's been confusion over what Promoted Posts are and what they are most useful for. Facebook software engineer Phil Zigoris, who is one of the main engineers on the Promoted Posts product, laid out the facts for Inc.com. Here are his top five things small businesses should know about Promoted Posts.

1. How Facebook's news feed algorithm, known as EdgeRank, works.

"EdgeRank is a term that has been used in the past to describe how we optimize the content of news feeds based on what is most interesting to you [as a user]," Zigoris says. "We don't have a product or system called EdgeRank. The news feed algorithm takes many factors into account when it's deciding what to show, including how often two people interact, how many people have liked, commented on, or shared a story, and the type of content that is being shown."

In other words, you may be more likely to see a story about friends who got married, with lots of likes and comments, than one about a friend who got coffee by herself. Facebook itself has noted that page posts are often seen by as little as 16% of fans. 

2. How to get your post seen by more people.

You can plan, create, and post smart Facebook posts that lots of people will like, comment on, and share. That's about the only answer here. Organic sharing and virality give your posts their biggest natural boost--and cause Facebook to show them to more people.

"No, nothing has changed about how page posts are shared with the people who like a page," Zigoris says. "The best way to have your posts seen by more people is to post things you think they will like, comment on, or share with their friends."

The nonorganic option is to buy Promoted Posts.

3. A page administrator can--but doesn't have to--pay to make sure more fans see posts.

Promoted Posts can let admins reach people in a way Facebook says is "simpler" than using the Facebook Ads ecosystem.

"We heard from people using Facebook, especially small and local businesses, that they wanted an easier way to promote upcoming sales, concerts, etc.," Zigoris says. "Promoted Posts make this really simple to do. We made this easier so page administrators can focus on creating quality content instead of managing the complexities of an ad campaign."

When a page administrator chooses the Promote button underneath a post, a drop-down menu will give an estimate of reach based on monetary increments of $5. 

Content that is not specifically promoted will still be seen, and content that gets lots of likes and shares will be seen more often. But promoting posts increases the potential reach.

4. How to measure which posts get the most traction with your existing audience--and beyond.

"Page Insights is a great tool to help you learn more about the types of posts that really resonate with your audience," said Zigoris. "For example, you may find people engage more with posts that include a photo or a question. After you promote a post, you can click on the Promote button again to see how many actions, such as page post likes, page likes, or link shares were a result of the promotion."

5. Best practices for choosing posts to promote.

Zigoris said that deciding which posts to promote will be different for every business.

"Page administrators should use Insights to gauge which posts are seeing the most engagement, and then optimize with that information in mind. We've seen people who have found success with posts that contain photos and videos (such as new products), offers, exclusive events or news (like daily specials or upcoming in-store events), and questions (like getting feedback on store favorites)."

For more information, Facebook offers case studies about Promoted Posts, as well as a marketing classroom with regularly scheduled webinars.

Let me know if you have additional questions or concerns about getting the most out of your business's Facebook presence in the comments below.