Hey,

I am wondering what trigger is?

Thanks.

It's actually answered quite well in the FAQs, under Premium Member and Gold Coin questions.

3. What is a trigger?

Triggers allow you to get notifications on your email every time when certain conditions are met. For example, you want to buy a Male Dragon with dominant Napalm Gland and Spitting Muscle genes (yes, you want him to breath fire!) and Genetic Power 1. You go to the Pet Triggers and check there the following settings:

After submitting this trigger, you will get an email notification every time when such dragon appears on sales.

The same thing can be done with the Breeding Offers and Items.

What's not mentioned in there, you can manage your Triggers if you go to My Account -> My Triggers in the menu bar.