I don't know if anyone participates in the Sony Rewards Program, but I think it's worth a look into, as there are several ways to earn reward points in addition to purchasing/registering Sony products.
They have a Wheel (of Fortune) Watchers Club where you earn 10 points for entering the bonus round puzzle answer each night (M-F).
There's the Sony Pictures Television Club where you earn 10 points for answering the Daily Question, which can pertain to any of their shows.
In each of these clubs, if you answer more than 8 (Free Play level) or 12 (Jackpot level) correctly that particular month, you are eligible for either 10% or 15% respectively off products in the Sony Rewards catalog. You also earn points for taking part in polls, keeping a wishlist and updating it every month. Also participating in the Wheel Watchers Club Rewards Flashback question they post twice a week (M/W). There are other clubs as well, but these are the ones I participate in. There are also monthly contests.
** Word of warning** I got burned April 1st when I lost over 6000 points I was saving up towards the Daily Edition, because points expire on March 31st. I thought it was an April Fool's Day joke, but no such luck and I was crushed! If I had realized that they expired I could've purchased a SonyStyle giftcard with the points I had. My fault for not reading the fine print & lesson learned the hard way. Nevertheless, I'm still hooked and am up to over 2500 points now.
... all that to say that they have just added coupons/giftcards for the Sony eBook Store in $25 & $50 amounts, which is equivalent to 2500 & 5000 rewards points.
So, I'm totally excited that I can redeem my points for eBooks!!!