I use Uploadcare because I was in need for a scalable and stable photo upload and manipulation service for a customer of ours. Uploadcare api is easy to learn and use, accompanied with a great service and support.
Uploadcare has saved me countless hours/dollars/grief by offering an amazing file management & processing platform with a phenominal user interface that I can embed right in my web app. It terrifies me just thinking about life without Uploadcare. I recommend it to everyone I know!