Well to an extent that depends on your needs. Some people find they get what they need from just listening once but continue to listen to their selected download to reinforce the changes or because they just love to relax so much.
But, as a general rule, we recommend you listen to your session once a day for a week, then after that just as often as you feel you need to until you get the benefits you are looking for. However, if you want to listen to it more than once a day, then that's no problem!
Once you have got what you want and need from the session, you can listen to it occasionally when you feel in the need of a 'top up' or, as we say, simply to enjoy relaxing.