Social media sites have a feature called “trending” that highlights keywords or phrases that are currently popular. This can be as broad as current events or gossip, or it can be more targeted to an industry or even a specific brand. Trending can be a powerful tool for businesses to get their content in front of new audiences, but it’s important to understand how trends work before using them to your advantage.

Trending topics are generated by algorithms created by the social network site on which they appear. These algorithms take into account a variety of factors, such as location, the people you follow and what other searches you’ve made on that site. This can make what’s trending in one city different than what’s trending in another, and even differ by user.

The exact algorithm is a closely guarded secret, but there are some general rules that seem to apply. Topics must be relevant to a large number of users in order to generate enough interest to trend. It’s also helpful if a topic has viral appeal, meaning that it spreads quickly among the social media community and gains popularity on its own without being promoted. Controversial topics are also more likely to trend.

Some trends last a short period of time, while others have longevity. Twitter’s algorithm takes into account both how long a topic has been trending and how rapidly its volume has increased or decreased over time, explains data scientist Gilad Lotan. The latter is especially important because a sharp spike in popularity could be a result of a fake trend, such as someone using the hashtag #JustinBieber. Twitter has a built-in decay algorithm to help eliminate these false trends.

When determining if something will become a trend, the social media site will also look at how many people are searching for that particular phrase or keyword. Twitter also considers the speed at which the topic is growing or falling, and the likelihood that the trend will continue for a significant period of time. It will also factor in the likelihood that the term will be misspelled, as a mistyped search can split the trend and cause it to disappear from the list more quickly.

Businesses looking to capitalize on a trend should avoid posting irrelevant content, as this can draw the ire of the site’s moderators and lead to your account being suspended. Trends should be relevant to your product or service, and a little bit of research into the latest trends in your industry can help you decide what kind of content would perform best on your social channels.