Having unique content matters, it can sometimes even double the traffic you're recieving. I used to submit with (overpromoted) sponsor content, sure i got sales and traffic, but it wasn't really that much at all.
A few months ago i decided to buy content and submit that instead, my traffic has doubled ever since.
Also, make sure you're using a max of 2 outgoing links and one 2257 link/text at the bottom of the gallery. Make sure the gallery looks nice, clean and trustworthy.
Good luck! Gallerysubmitter.com rocks
