Americans like to buy lottery tickets?

I have a few American friends who routinely spend at least $10 every month on lottery tickets.  They usually get the cheaper tickets ($1 or 2).
My Chinese friends rarely buy lottery tickets.  Of course, if you go to a Casino, you will see many Asians.
It does seem very popular among the Americans to get lottery tickets.  Peopel at 7-11 tell me the lottery tickets bring them traffic.

I remember taking a class before and the professor said they are not buying lottery tickets.  They are buying hope.