I am quite new on SE but what I notice is (generally speaking since I have no statistics) that, and this is almost true for most new users, many answers are not accepted neither upvoted. When someone spends time providing an answer, I think that the minimum would be to react in some manner (positive or negative, I don't mind).
Don't you think that, after an answer is posted, an automatic message in bold could follow telling something like "please accept this answer if useful to you and/or upvote or downvote it". In the same spirit, if an anwer or comment is downvoted, don't you think that it would be good to know why ? I recently asked, in a polite comment, for clarification of an answer and I got a downvote (I am not sure this is the appropriate word but my "score" lost one point !) without knowing why and who did it.
As I said once, in S.E., the E stands for Exchange and this is to me the most important.

• I would never downvote an answer to my question, unless it is particularly horrible. But I will usually upvote mediocre answers.
– Asaf Karagila Mod
Nov 24 '13 at 8:20
• It's possible the OP has less than 15 reputation, and so cannot upvote or downvote answers. Nov 24 '13 at 9:13
• @Joel: Or they might be unregistered.
– Asaf Karagila Mod
Nov 24 '13 at 9:22
• I was just thinking about this feature request a minute ago. But I dislike the idea of pressuring people to accept answers in a hurry. I think users should take time to accept an answer, perhaps getting a reminder every now and then whenever they have answered questions without accepted answers. Nov 24 '13 at 11:23
• @GitGud. I totally agree with you; there is no hurry nor pressure. It would just be to remember them that someone took time for looking at their problem and that they can (may, must,...) provide their opinion ... one of these days. Nov 24 '13 at 13:19
• If it makes you feel better 90+ of my answers are unupvoted. 15 or so of those have been accepted, though. Many of those were to questions by unregistered askers or newbies, who cannot vote. And it's not just me. Brian Scott, one of the most active and appreciated answerers, has something like 750 unupvoted answers. Based on that statistics you should expect may be 10% of your answers to go unappreciated. Not nice, but them's the breaks. Also those of us not living in US timezones have a handicap in the sense that our answers don't spend time on the front page during the peak traffic hours. Nov 24 '13 at 17:48
• @JyrkiLahtonen Does MSE hit its traffic peak when americans are awake? Is there anywhere I can see that? Nov 24 '13 at 23:12
• @GitGud: Just a gut feeling. Or my sour grapes for having posted many IMHO good answers in my morning hours (when US members should be sound asleep) that never catch up in votes even if I solve the problem and the earlier answers fail. This happens too often to make me grumpy. On a good day I can shrug it off, but not always. 1:30 am now. Off the air. Nov 24 '13 at 23:24
• @GitGud: If I had to guess — and it definitely is just a guess — I’d guess that there are peaks for the U.S. and for India. Nov 24 '13 at 23:24
• Maybe one could limit the total number of open questions per user (for example min. $\pm 50%$ solved questions before a new one may be opened) Dec 4 '13 at 13:25