Even if your item is rejected from one site, it may still have value elsewhere

I once uploaded a sound effect to another stock media site which was rejected. Since I thought it sounded great, I decided to upload it here on Pond5. That same sound ended up resulting in my first sale. :)

Lesson learned: One man's trash is indeed another man's treasure.

So True. It's good to have more than one site. One may reject a file while another accepts it and it sells very well.