It would be stupid for them to pay for advertising if we can't use their sites. There still might be some poker ads though.
It will have a minimal effect to online gaming. You WILL still be able to gamble online with ease from within USA. Instead of tranferring money directly from your bank to the gambling site, all you will have to do is open an account with an online bank eg paypal or click2pay. store your money on there then you can transfer it to any site you wish. Everyone is worrying about problems this new regulation may cause but i cannot see it hindering people. You will be able to find ways around it such as what i have just suggested... Great news for online pay/banking systems like Paypal hey?!?!?!? Jazz
US based Paypal will be prohibited from transacting with an online gambling site once the law goes into effect, as will any other US payment solution -- the sites themselves now say they will not accept US customers.