There is always a chance to get traffic without backlinks but I think you have to focus on long-tail KWs.
The shorter and more competitive KW you are focusing on, the more difficult it is to rank without, or even with, links :)
(Without links is impossible to rank well on highly competitive KWs...
What do you mean by "natural linking"??? Getting a good link in gambling without paying for it is almost impossible for me, although it happened a few times. But I do not think it is something we can rely on. Gambling is really competitive industry and the best natural links we got were always...
This thread is very useful. I never know how to compare the % RS when there are so many factors involved.
If you are going to audit 7starpartners as well, it would be great! :)