Do you primarily post photos with no content to your brand’s Facebook page?
Ditch the Digital Dump Truck!
All three platforms have strong and compelling benefits. Facebook pages can be really great congregation points for your fans to crowd around and talk about your brand and engage with your content. It even has great photo tools and sharing. And it is true that photos have dramatically higher engagement than simple text posts on Facebook. But if the ONLY thing you are posting is simple photos on your FB page and expecting tons of likes and shares you are likely not building engagement. And although this Facebook page tips for business is solid:
It takes a strategic and varied mix of text updates, photos, videos and other great content to build your brand with fans.
If you are posting a large number of photos then consider using Instagram and/or Pinterest to post the photos to. You can easily cross post them to twitter and even Facebook if you want. (although I ALWAYS strongly suggest you customize your content to each platform based on your customers, the platforms specs etc.)
Bottom line: use each platform as if you cared about the community that is on it and engage with them rather than hurl photos at them. That goes for Instagram and Pinterest as well.