Keep the prizes and points and notes but do not use a point based leaderboard to give out the prizes . Anyone can qualify for those prizes by being active in the community ( Active status will need to be defined but should be more than one post a month). This way you will encourage others to be active on the site. So one month 200 hundred people may qualify and other month 2000 could qualify. This way it will help those that do not use social media that much to be active and know that they will have a chance to win (right now points wise they lose 20 points a day potentially (gallery share, and thread share), right @Chiquinho. So even if you got no points from referrals, they may never have enough points to be in the leaderboard as they would lose about 300-600 pts to others who use social media.
Plus I think the points push for the leaderboard lends itself to a saturation of the community threads and post, and potentially to burn people out.
Another thing is that you can not totally eliminate the points and notes process as I think that is sort of their new initiative (Anker has their referral section too). If you do the prizes as stated by being active, it still makes it valid, make people feel like they have a chance and reward community members that bring in new people and sales. I do think that a referral for a sale should hold a higher value than a referral to the community.
I think also to increase the 6-10 to more than 5 giveaway tickets and potentially do a combination of tickets and notes.