Figure out how long the poll stays on the home page. For each group, scale that group's number up by the reciprocal of the probability of a person seeing the poll conditional on their membership in that group. (This conditional probability will be equal to min(the amount of time the poll stays on the home page divided by the average length between visits for a member of that group, 1).)
This assumes a person's visits are evenly distributed with time, and that members of all groups are equally likely to respond to the poll if they see it.
Probably less frequent visitors are less likely to have registered accounts and therefore less likely to respond to the poll if they see it.
This assumes a person's visits are evenly distributed with time, and that members of all groups are equally likely to respond to the poll if they see it.
Probably less frequent visitors are less likely to have registered accounts and therefore less likely to respond to the poll if they see it.