[William]

True, I am not from the US and I don't really know how agressive sites are in their advertising.
As I see it, some sites decided to not take a chance and banished US players, others decided that the great profits they could make out of US players was worth the risk and allowed americans to continue playing at their site. It is obvious that once they have taken that step, the smaller the site, the more agressive the marketing. It seems normal that Stars being as large a site as it allready is, focuses in not losing it's customers (knowing that they will get some new ones anyway) rather that attracting many new ones.
To me it is the only logic explanation.