Being arrested is a complicated and uncomfortable experience. A person is booked, placed into a holding cell, and then wait for an arraignment, where he faces a judge (who is informed of the charges) and then gives his plea of guilty or not guilty. Then, the court will appoint a date for the commencement of the trial. This process can take from months to even years.
A person may wait in jail, or (if the judge deems him to be safe) remain out of the custody of the court where he can enjoy limited freedom. However, he must pay bail bonds.
Bail bonds are surety bonds that act as a form of guarantee of the total bail if the person does not follow through with the terms of his release. This may be paid by the bail bondsman who gives the court a blanket bond for several clients. The clients, in turn, must pay the bail bondsman ten percent of the total bail figure. This amount can not be refunded but those who are unfortunate (or stupid) enough to be arrested consider it money well spent compared to having to stay in a cell until the time the trial starts.
Bail bondsmen are usually available at all hours of the day, all days of the week, since they know that people will probably need their services even at odd hours (crime follows no bundy clock).
There is the risk of course that somebody will try to leave town and go into hiding the minute they are freed from the cell. That is why bail bondsmen will hire bounty hunters, who will run after these people and drag them back to court, if need be.