I do some freelance work, and own part of several companies. Most of the companies I own I no longer work for, and I do very little freelance work these days.
Usually people apply for many jobs, to get a job. If they get multiple job offers, the polite thing to do is turn down the job offers you will not take, but often people are not polite.
The first data is the number of people applying for unemployment, followed quickly by surveys of labor force and employers, and finally looking at payroll tax data. It is important to remember that labor statistics exclude illegal, and under the table jobs, so payroll tax data, while being slow, is absolutely accurate. This means they can get the initial data better and better, until it is fairly accurate.
Labor statistics are probably the second most accurate economic numbers, with only federal spending being more accurate. Inflation statistics are less accurate than either, but are easy for anyone to check over time.