Hey Charl,
A sponsor doesn't necessarily want the best rider although that can help. A sponsor is looking for a good ambassador for their product. Generally someone who is having the most fun on the water, who rides with a smile on their face, who is out there all the time making the sport look like fun to the
average Joe.
A good sponsored rider is super approachable and willing to give over their time to help others. It also helps if you are well spoken and can write reasonably well. It helps if you can put together legible and coherent stories and gear reviews for forums like this one and also kite magazines.
A good team rider is always keen to assist the rest of the team and the designers with input if and when possible. It is a must to know what a good board is and what a good kite is and what precisely you feel needs to change to make it better for upcoming prototypes.
On top of all this, it is a general must that you attend competitions and represent the sponsor in a professional manner, even if you don't win. The tricks you are doing are not cutting edge enough to win a spono on riding ability alone. To be noticed for your riding you need to lead the pack, not follow it!
Easy eh? Good luck with it ;-)