Weekly sports polls get fairly good responses in terms of people participating in the poll but generally less zaps and comments than the regular daily post.

I try to make them as creative as possible with not just straight forward yes/no options. Overall I think they are good and I like to use them and participate in them but maybe not the best route to go if your aim is to stack zaps and encourage commenting. I do usually leave an Other (comment) option in my polls to encourage people to engage.