An interesting study from the Journal of Consumer Research has been released, which says that online gamblers play for longer and tend to perceive a greater sense of control than people who gamble in a casino.

Their study found that, unlike casino gamblers, who seek thrills and social experiences, online gamblers seek the anonymity their home computers provide. "For casino gamblers, gambling provides a perceived social connection with unknown others in a sense of shared fates and temporary community. Online gamblers, on the contrary, perceive a lack of social connections in the online realm."
Full story here ...

Buzzy thinks that online gamblers may play for longer stretches because you get more bang for your buck, as well. I have yet to see a $.25 blackjack table in Las Vegas.