Well it needs some work, and I am just pointing out what I see to help you improve
1. WAY TOO BIG.. forum signatures should be around 450x175 In my opinion.
2. Remove that watermark at the top, or whatever it is.
3. The background is too plain, it needs some zaz, some "WOW"
4. The render looks scrunched. When re-sizing a render, always hit CTRL+T, the when you are about to drag the corners, hold SHIFT.
5. You need a clear focal point.
6. You need depth. At the moment, it just looks like text + watermark + render on top of background.
I know its a bit harsh, but that is just what i see wrong. Could look stunning if you resize, add some c4ds, add some effects, the works.