I got a packet, too. Since I enter a lot of contests and sweepstakes I tend to get random stuff in the mail every once in awhile, but I noticed this one was from Switzerland
and knew I hadn't entered any contest originating in Switzerland. Nice little promo! The deck of cards is a good idea. Poker players will not only use it, but they won't be able to help but remember King Solomon's when they do.
I play there from time to time (thinking I'll eventually clear at least part of the bonus) and don't mind the interface. I mostly play .25/.50 limit tables and am currently up about $15 over my initial deposit. The only weird errors I've seen have had to do with other players being displayed as "all in" when it's impossible for that to be the case, and the software hanging at the same time. I'd definitely be hot if it decided to crap out during a situation like tenbob mentioned with the quads!