The tickets are totally random. Sometimes you get it, sometimes you don't. It's random.
I don't think they are actually random. I think they are partial. If you look at the rewards for a task or event some of the rewards have a circle around them and some have a partial circle. Those with the partial circle seem to indicate how many times you need to do that event to get those rewards. For example in the events the events give green tickets, simoleons and blue tickets. Those don't have circles around them and are given all of the time. Blue tickets have half a circle around them and you will get blue tickets once fore every two times you do an event. Purple tickets have a quarter circle and you will get purple tickets once for every 4 times you do an event.
Well i got it on that day and it was the only party i went to
