i got the same email, i think they are testing the calculator, if you look on their site it says "Welcome to the Poker Odds Calculator Test Version" i have put it on my site and they are working on articles for me to use on the my sites, i dont think its that bad of an idea, they say you will get original content that will only be used on your site and they will write about whatever you like. As far as the links back to pokerlistings goes, im not to thrilled about that, but im going to test it out and see how it goes, its not a bad site to be involved with! you can take a look at the calculator on my site
Odds Calculator