I'll start off on a good note and congratulate everyone in the community for continually supporting each other. We have maintained a great answer rate here on 3D Printing SE with a answer rate of 96%. I believe this rate has been maintained since day one and it's hard to keep up, especially with fluctuations in user activity.
However, I would like to at least address an issue I've seen trending. Most of the issue comes from old posts and new, unfamiliar users to the SE network. Anyways, there is an abnormally high number of unaccepted answers.
Specifically, on 01/28/2017 9am Pacific US, there are 658 questions with answers, 258 of which have no answer accepted. This is an answer acceptance rate of about 40%.
Updated to 11/16/2018 10am CET, there are 1682 questions with answers (of a total of 1788 questions), 706 of which have no answer accepted. This is an answer acceptance rate of about 42%, although improved, it is still very low!
Now, I've done this in the past with little payout, but perhaps if we have more eyes on it moving forward. I have gone through the list of questions here and commented on the question to ask the OP if any of the answers helped solve their situation. Something like this (see also meta posting Do we have Standardised Comments?):
Hello @[UserName], I noticed your question has been up for a while now. Have any of the answers below been able to solve your question? If so, would you mind accepting the appropriate answer. If not, what is missing so that we may help you further? Also, if you have figured it out on your own, you can always answer and accept your own solution. Thank you.
This should hopefully ping the user. Also, going through these questions may bring up questions that may need moderator attention/intervention.
Hopefully we can tackle this issue and get some other users more reputation in the process.