TradeShark Tennis appears to go above and beyond, with a small one-off payment giving you access to a trading mentor for life.
The service is run by Paul Shires, who says he was able to quit his job in 2010 to start trading tennis markets full time.
Paul originally set up the website as a blog and a trading community to help newbie traders to learn the ropes. Since then, Paul has put together a service with a wealth of information that is valuable for both beginners and more experienced traders alike.
There is a detailed Betfair Tennis Trading Guide which includes simple, low risk strategies that are also demonstrated in video guides. As well as this, there is general advice on staking and money management and a helpful section on what to do in different trading scenarios.
He also offers trading tips via email for every main tour match, with his own personal favoured trades highlighted each day.
Community and support seem to be the heart of the service, with Paul on hand to give advice along the way and a member's Skype chatroom that he also attends.
It seems like a bargain at £39 for lifetime access, but we are going to try out TradeShark's trading advice and strategies for ourselves to find out for sure. It's recommended to use software for trading on Betfair, so we will be using Fairbot in our review.
We will be back next month with an update of our results.