Do we need? Dd3 is getting her first yoto for Christmas, and I imagine ds5 will likely be getting one for his January birthday (waiting to see how keen he is).
But how many cards do we need? I've been building a huge playlist library for my cards, of books and music, but I've no idea of they'll just listen to the same 3 over and over, or whether a full library of 20+ physical cards is preferred? I've ordered 3 story cards and 11 myo cards so far.