Someone mentioned here on this forum that one could get $100 credit if he signed up for the SonyCard account when purchasing a reader from Sony Store. I tired it since there was nothing to lose.
I ordered a reader and signed up for a SonyCard on November 15. The reader was delivered to me on Nov. 30 and I got $100 credit on December 14.
I was a bit skeptical about it but I ended up buying a reader for $ 271.86 (including tax). That is not a bad deal.