Think of money that you can get your hands on before you've earned it as a growth accelerator. You could for instance stave off a potential competitor by grabbing a larger share of the market than you would have been able to do if you both relied on organic growth. In the arms races that start-ups are bound to find themselves in sooner or later a couple of million in hard cash can make an enormous difference in the long term outcome.
But that's really looking at the tea-leaves, I have 0 evidence for any that.
It would make some sense though, given that they've ironed out a lot of the issues they had initially, their price points have been adjusted to the point where a lot of the users are happy (and I find it commendable how they worked with the userbase establishing how much was reasonable), the only thing they have to do now is sit back and watch it grow.
But they may have decided that sitting back and watching is not their style.
Time will tell, but I'll certainly be watching for any major announcement.
$10 million is a huge amount, it sounds like they have huge plans.