You are one of the rare few who have actaully been invated, there's also the Pallas series, same as the Juno, its some kind of marketing they aim for and give out tickets to some people, dunno what criteria it is for selecting but i tell you one thing, I have played at pokerstars for 4 years and collected well over 100,000 fpps lifetime and I have never been invited, who knows, but still a freeroll of $100 with 500 players aint a bad deal, good luck