Constant harassment to upgrade to premium membership. Email after email after email. Promising you that you'll make a profit off your images if you hand over money to YouPic. Surely YouPic will be the ones making a profit off my images by me paying them? You are also limited to only being able to upload 2 images per day.
The site itself is smooth running, people can like, nominate as an inspiration or 'repic' your images. There is no real critique to guide photographers, just the courtesy "nice pic".
It lets itself down in the points system it operates. The more likes, comments you get and the more you like and comment you make you get points. YouPic is riddled with high ranking photographers who comment on everything just for the points. Some of the top ranking photographers do not have a good set of images in their gallery and i can only presume endless likes, comments etc have put them there. Also the more followers you have the more likely you are to have a higher ranking regardless of your quality, people tend to like images because they're following someone and knowing in return they'll get likes back. That's the huge fault for this site.