Personally, I pretty often search HN with Google, and read old comments. (Basically, when researching some topics, I query Google twice, second time with site:n

Personally, I pretty often search HN with Google, and read old comments. (Basically, when researching some topics, I query Google twice, second time with site:news.ycombinator.com added.) So upvoting probably makes sense. That said, I also read a lot of posts ‘later’, but often forget to upvote. (Unless I return to read comments—Readability doesn't work for HN comment threads, unfortunately. Partly I blame page markup for that.)