Post the image link.
What it could be is that your picture shows up as similar to one of the free pictures. I've had it happen before. Picture got few thousand views for no reason except it was deemed similar by the algorithm (it wasn't at all) to a free pic.
I just had an image accepted and within hours it gets views over views. Currently within the last 2-5 hours i got 67 views on that image. I looked all over DT, but couldn't find out if it is because it is placed somewhere on the starting page of DT. Anyone had that before?