So what is with that little sign? In Canada and the United States, it's called number sign. But in Europe it's called "hash" and that's where the name used in Social Media comes from the hashtag.
A hashtag is simply a label for social media posts that makes it easier to find similar content. It's easy to see how this can become a great opportunity for making business. You can find out what are customers interested in, and most important, you can use your own hashtags to make customers interested in YOUR products or services.
In certain sites, you can track the hashtags that are being used the most worldwide in live time. There have been marketing campaigns so well-done that they have come to this top, being one of the most talked about subjects in the world. And while that doesn't mean every social media user who engages with the hashtag campaign will engage with the company that made it, it is a huge step visibility: something that can make all the difference in the world.