Humans are god awful at probability. Weird patterns happen way more often than we intuitively expect.
I've won three times in one day, I've also gone six months without winning anything.
I make the average click worth around 0.03c (three ClixGrid are worth one Micro click). I arrived at this figure by collecting a bunch of stats posted in the forum, adding them all up and dividing it. 0.03c isn't a great deal, but it's more than some sites pay you to watch videos, so...
The real value is in unlocking your activity bonus. The winnings are just a bonus.