I used to do Crowdsurf hits ALL the time, just to make a little money and pass the time. But, even with a bonus, if you end up making 8 cents for a little less than a minute, plus waiting on a hit to load, or sifting through audio you can't understand, or it seems too difficult, etc, it usually ended up being like 5 cents per minute after taking all that into account.
So, the rate already is bad, but take into account the time spent, you're making almost nothing. And Crowdsurf has a bonus structure that is REALLY hard to get (125 hits at 3.75 rating /etc) as the reviews are REALLY weighted. Miss a small thing it goes to a 3, miss something that isn't actually wrong, but the editor thought it was, your score is even lower.
I won't touch them nowadays.