Adding new unique content to your rakeback site is extremely important.  The reason is that many new players are not searching for rakeback related terms.  They do not know that rakeback exists.  Your goal is to get these players to your site through the terms that they are searching for and then introduce them to rakeback, sign them up, and pray that they turn into winning players.  To do this you need related content on your site that is not about rakeback specifically. 

One way to do this is to create content about poker software, poker room reviews, poker strategy, history of the game, or any other number of poker related topics that players may be searching for.  This means that you have to write articles or pay someone to do it for you.  Using freelancers to outsource your work is covered in a different section of this site and is an outstanding way to get things done. 

When you create new pages, you have to continue to use your <h1>, <h2>, and <h3> tags, titles and descriptions, and alt text.  You also have to include your keywords and phrases in your content.  There is something else that will help you though that you should do before any of this.  Create search engine friendly urls.

A page targeting the term “PokerTracker vs PokerOffice” should not have a url of /software.html.  It should have a url of /pokertracker-vs-pokeroffice.html.  Using your keywords in your url is very important and extremely easy to do.  There is no reason not to do this as you continue to add content to your site.