The ioby gratuity is optional, but crucial. When you check this box, we'll add 20% (similar to a restaurant gratuity) to your ioby donation. Your donation (all of it) still funds the project you picked. But your gratuity keeps ioby's lights on, our computers running, and our rent up to date. So check the box! and help us to continue creating grassroots change in your backyards.