I know that Jury Duty in the US (across all 50 states) is mandatory for citizens when they're given a summons (names are selected at random from the electoral roll) and it's an offense for failing to appear at the appointed date & time (ranges to fines or imprisonment). Usually, the courtroom allocated is based on where you live (i.e. if you reside in Oceanside, CA then the adajcent court is under San Diego) you get the picture.
Have you ever received a summons in the mail? If so, how many people showed up to the courthouse in your area? You bring the summons with you in court (as in the physical form) or show a email from a digital copy. People who also have the summons line up behind and in front of you waiting for each turn at the court clerk asking whether you're capable of serving a 2-3 week trial or longer (you can apply for excusals).
That is only, if you have evidence to back it up (it varies from caring for an elderly relative, mental illness, physical medical ailments, etc). when wanting to be excused and exemptions apply to certain jobs (member of congress / white house, a DA or attorney, cop / sheriff, active member of the military) & ex-cons who are charged with felonies or related offenses are disqualified from ever being subjected to JD.
Now, if you have waited in the jury panel in court: where your number is picked at random in which if it's called, you acknowledge your presence (it's up to lawyers to decide whether you're designated as a juror). You can't leave the venue unless you're told so. If you've showed up for JD: have there been cases of people deliberately failing to show up even though it's mandatory by law to appear (as they received a summons)?
If you managed to wait there the entire duration of the day without being selected, what is the payout like? Is it below or within minimum wage? However, if you have served as a juror: what is the total payout for a trial? Also, are you allowed to discuss the case mentioned outside court or is there a strict NDA (they explicitly say you cannot brag or mention the case on social media or to any other third party).