Celebrations, Adventure Labs, Virtuals and Souvenirs.
There is no physical cache involved. Gifted to members by GC HQ. Sometimes "earned" by meeting set citeria. Some times just a lucky ballot draw. Maybe even a combination of both.
Mostly, they can be a lot of fun. You meet fellow geocaches and make friends. You get to visit different places, see nice scenery, or learn interesing facts. And you have digital reminders of you "achievements".
A cynic might conclude:
We can create a celebratory event anytime. Ad Labs are sort of like a string of virtuals - reincarnations of a type grandfathered years ago. Souvenirs are personal virtual digital awards - you only get to see them on your Souvenirs page. And maybe in the odd Challenge Cache or two.
Love them or hate them - they are here and we deal with them. They are a kind-of lazyman's cache. You don't have to do much.
What's your take?
Anyway, let's have a short MultCache to cheer things up. At the posted coordinates, on a sign on the fence, you can see the ten digits of a mobile phone number. Use these number to calculate your cache hidden at S27 36.ABC E153 07.DEF
A= 4th digit
B= 6th digit plus 3rd digit
C= 3rd digit
and
D= 5th digit
E= 5th digit less 3rd digit
F= 7th digit less 10th digit
Here is a Checksum (A+B+C+D+E+F): 26