Starting this weekend, LessWrong will be displaying karma notifications in the top-right corner, telling you about when you've been upvoted or downvoted. You can click the star icon to see which of your posts and comments have been voted on, and how much their score has changed.
This works a little differently from how most web sites do it. I've noticed a tendency, in myself and others, to sometimes obsessively refresh pages hoping to have gotten Likes. The rest of the LessWrong team has noticed this too. That's why on LessWrong, by default, this won't work; karma-change notifications are grouped into daily batches, so after you've checked it, you won't be notified of any additional votes until the next day.
While I hope that this prevents people from using LessWrong in ways that they don't endorse, daily batching might not be a strong enough safeguard for everyone. If you find yourself tempted to check LessWrong more often than you think is ideal, you can change the karma-notifier batches to weekly, or disable them entirely. On the other hand, if checking and posting on LessWrong is something you'd rather do more of (because you'd otherwise do something less valuable), you can set it to real-time.
As a nonprofit with no advertising, LessWrong is under a different set of incentives than most websites. We worry a lot about the trade-off between engagement and addictiveness. I want people to use the site in ways they reflectively endorse, even if that means using it less. I think LessWrong should leave that under user control, as much as feasible.
(As a reminder: Voting on LessWrong is a way of saying "I want to see more/less things like this". Upvotes are a way to tell people that their post or comment was worth their time to write, and worth your time to read. It does not necessarily indicate agreement; sometimes a good write-up of an ultimately incorrect idea is what a conversation needs. Conversely, downvotes do not necessarily indicate disagreement; sometimes a correct points is written in a way that's confusing, inflammatory or otherwise detracts from the conversation.)
As always, bug reports are welcome here, via the Intercom widget, or on the GitHub issue tracker.