One of our users is doing a 365-day gratitude challenge -- one 21-day challenge after another, making up her own custom ideas as she goes.  A participant in that challenge, now well into the triple digit days, wrote this:

"I can't imagine not doing another challenge and many of the new ones  that have started. Just can't imagine a day without KindSpring, even if I just hang out on the Community Feed for a while.  Thanks for all the work you kind folks do to help us all grow into making this world a better place."