Why should you be advertising on Facebook? All you need is one simple statistic... 1.79 billion people visit Facebook every month. That is almost a quarter of the world's population.
Think about that again for a second. One quarter of the world's population are available in one place, for you to target with your message.
With the right targeting and segmentation, you can reach exactly the right people for your product or message. Now add in Instagram as an ad placement, and you have opened up an even wider audience for you to target.
Still not convinced?
Facebook ads is a platform that literally anyone can get started on in minutes, and be advertising to the world in no time. Whether you have a video to share, or want to get people to like your Facebook page, or want to capture lead data such as email addresses, or you want to retarget your customers to get them to purchase items in your sale, then Facebook ads are the place for you.
Check out the audience targeting available on Facebook: http://knowledge.driftrock.com/the-driftrock-facebook-101/audiences/what-audiences-can-i-target-on-facebook