Hi there Pixicat7. On of the main issues when using Spotify and data usage is that while you indeed can streamm music and not affect your data allotment, viewing ads or clicking on links or watching small videos ads, can incurred in data usage. We strongly recommend to avoid this in order to not use your data usage. Also, you may want to turn off your Data if not on WiFi and when your are out and about and do not need to access the data network. Hope these tips and clarification helps you manage your data.