Every minute, Facebook users "Like" over 4 billion posts. The average person spends almost 2 hours on social media every day, a huge chunk of that dedicated exclusively to Facebook.
You can pinpoint your ideal audience, and show them your products or the service you provide 24/7. The more they see you, the more comfortable they will be with you when it's time to buy.
When it comes to advertising data is king, and Facebook is the powerhouse of data with over 2.8 million users. Since FB has the most data on daily social media users, they can charge so little to show them your ad.
When you use Facebook ads manager, you get an in-depth breakdown of how the ad's performance's doing. This way you won't have to guess what works and what doesn't anymore
Facebook gives you the option to re-target everyone who was already engaged with you, either on your Facebook or Instagram account.