user172: On each question upvote (but not answer) I'm getting a link share window popped up. Is it by design?

user56: Yes, and it's happening across the network.
The idea is that you think the question is great (you've up voted it) and now you might like to share it with your followers/friends so the site gains more users, and you get the chance to gain a couple of badges.
I guess the issue is we're at a low question count at the moment so any question becomes "hot" as soon as it's voted up.

172: <p>On each question upvote (but not answer) I'm getting a link share window popped up. Is it by design?</p>
 56: <p><a href="https://meta.stackexchange.com/questions/101383/upvote-permalink">Yes, and it's happening across the network</a>.</p>

<p>The idea is that you think the question is great (you've up voted it) and now you might like to share it with your followers/friends so the site gains more users, and you get the chance to gain a <a href="https://bricks.stackexchange.com/badges/59/announcer">couple</a> of <a href="https://bricks.stackexchange.com/badges/60/booster">badges</a>.</p>

<p>I guess the issue is we're at a low question count at the moment so any question becomes "hot" as soon as it's voted up.</p>
