I remember some time ago that coke cans would have offers for discounts on Six Flags tickets. I know that Disney World has package plans. Some theme parks also have season tickets that you can take advantage of if you don't live to far away. Other than these, do you know of any options for theme park discounts? Do you use a travel agent or website? Are there coupons or Groupon offers for such things? How do decide which theme park to visit? Do find ways to save before deciding and let price play a role in the decision?
Official theme park websites often have tickets as well as resellers. Finally, you might want to check local grocery stores and restaurants. Note, that's where you can get tickets to Dollywood (I'm from East Tennessee USA.) in my area. Anyway, I also read that military, senior citizens, children, etc.. can also get discounts possibly, as you'd expect.
I can not help you with this because theme parks has never been exactly a priority for me. so I never looked for information from them. But as I think this type of search is something common, you'll not have a hard time finding an interesting site for this.
Correct me if I’m wrong on the voucher that is cheaper than buying theme park tickets right there in their counter. We had been to Disneyland Honkong 3 times already and twice we had purchased a voucher which is 20% cheaper. In one of our trips to Universal Studios in Singapore, we also used a voucher, again it is cheaper by 20%. My nephew was the one buying the voucher for us. He is a member of a discount club.