Why do many people ask mathematics questions here and then ...

not acknowledge answers with a thumbs-up, a comment, by choosing an answer as the best, or voting.

Do they think we are getting paid to answer their questions?

Far worse is question deletions. I think maybe some students like to erase their tracks of having had to ask the question so their classmates do not see. I sometimes get a laugh out of thinking about a student going to their friends the next day saying how they "figured it out." Especially, when we present far more elegant solutions or do it in a way that students would never think of themselves, yet they are able to present such a "clever" solution to their teacher on their homework. Sometimes I see the exact same question asked multiple times a week, I tell the askers to search for their question and they will find several good solutions, although just last week I did that and saw that the previous askers had all erased their questions so their classmates *had* to ask the questions again. Talk about not helping out the community by deleting the questions and answers.

Anyway, beyond that people do not realize it is proper etiquette to do what you suggested

Yeah, I have been on here long enough that I do not care about receiving best answer or comments or thumbs up, etc. for etiquette purposes, but the point is that a lack of feedback does not allow us to know if answers were effective or not. Which is fine, but when I see askers delete their former question and re-ask it without different wording or anything, obviously they still have a question about something but they are not communicating what it is, just hoping someone does it in a way that makes it clear to them. You have better odds as an asker if you explain what you do not understand so it can be directly addressed, or if an answer has some details that are confusing they can follow up and ask rather than posting a new question without giving any direction.

From an answerer's perspective, I don't really care whether they thumb up, comment, choose an answer or respond in anyway. I gain satisfaction already in knowing that I helped the person and reviewed my skills. It doesn't hurt to practice things you know over and over again, right? That's what I think anyway.

From an asker's perspective, if the question is dominated by all bad answers, or all answers that are good, I will leave it to voting. If they're all good, I leave a comment saying that I will leave it to voting since they're all well done. If they're all bad, I don't say anything and leave it to the polls for people to vote which they deem best. Other times (though rarely), I extend the question's time period, but forget to choose a best answer.

Ikr? wtf at least pick the first answer or something, jeez -_-