The study by Gambling Compliance also finds slim chances for a national law to regulate Internet poker. It predicts a major effort by opponents of online gambling to block it in Congress.
So far, three states allow Internet gambling: New Jersey, Nevada and Delaware.
The report says proposals for new or expanded Internet betting could be considered in California, Colorado, Hawaii, Illinois, Iowa, Louisiana, Massachusetts, Mississippi, New Jersey and Pennsylvania.
In California, one of the largest potential markets, Indian tribes are trying to agree on how to legalize Internet poker.
The report also says Nevada may consider expanding online bets beyond poker.