When you reach level 15 in the game a new value is added - Ego.
It can reduce the Starbits earned for missions.
Here I have reached 120 Ego, not much, but higher than my current Skill value of 53.
But no problem, luckily I have the card "Mid Range Mic" and you can take music lessons. With this you can't earn Starbits, but at least XP.
Because I go to music lessons, I can play less missions than before. Doesn't matter. It's not far to the first free booster pack and maybe the fancy Pink Lambo is in it!
A higher Skill value can also be achieved through cards. I have "Buster" a card with Skill 10. Quite good for the beginning. Better cards are also available in the in-game card market, I'll take a closer look over the next few days.