Each sample typically yields 4 vials of sperm. Generally speaking, 1 vial of sperm equals 1 attempt at Intrauterine Insemination (IUI). If you are considering IUI, doctors recommend 3-5 vials per child you plan on having (however, this is no guarantee).
If you're planning on using these samples for ICSI (Intracytoplasmic Sperm Injection), which is a form of IVF that involves taking one sperm and fertilizing the egg before transferring it into the uterus, 1 vial of sperm could be used almost unlimited amount of times since there are typically hundreds of thousands (or millions) of sperm in one vial.
We recommend multiple deposits since sperm quality is variable between deposits. Ideally, you would freeze multiple deposits and use your best deposit when you use it in the future.