According to Google "NO ONE" is searching for the keywords "rakeback staking", Which is why it was easy to rank for those words, especially since your domain has those keywords in it....
Not trying to burst your bubble at all, but knowing what your target audience is searching for is important...
"Rakeback offer" has 19 searces daily with a lower competition rate and you can probably rank for that keyword if you do some
SEO work and market your site properly.
You can also try to rank for the words, "rackback deal", or "rakeback deals", but the later is harder to rank for.
If you would like to know the best words to build your site around that are being searched for and are within your ability to compete with I can provide you a list of the best words to go for, for a nominal fee of $30.00
I have some very powerful software that I use to do market research and NO its not google tools, although this software does take advantage of Googles tools, it it much more intuitive and breaks things down to where you can see what are the best words to go for and what you competition is like....
If you would like to target other terms related to poker in general, I could also help you with that, for a nominal fee, then you can write some keyword rich articles and upload them to some article directories and start getting some targeted traffic..
All the best,