I recently came across this (admittedly, pretty old) question on Mathematics Meta: Do we want community polls? In summary1, it is proposed to have a meta post to find out information about the site's users. Such polls have been conducted on sites such as TeX, Mathematica and Academia2.
Would such a poll be in the interest of this site's community? Possible questions could address the community (nations, background (students, physics proffessionals etc.)), usage of this site or interests in physics. Though these are just suggestions (which are similar to those on the Math.SE post) and I would encourage everyone to add their own, should we decide to actually do this poll.
On the linked sites, the poll was a meta question/community wiki where the answers actually were the questions (the question body was used to lay out rules and some information). One would then comment an answer to the respective "question" (answer) or upvote an existing comment (instead of posting the same comment again).
1 I encourage you to read the linked Math.SE question since most of the suggestions there would also apply to Physics SE (I think).
2 However, I could not find any such poll on Mathematics, which suggests that it wasn't conducted, even though the response was mostly positive.