A 10-space coffee card pre-stamped twice will be completed faster than an 8 with no pre-stamps.
Fascinating stuff as always over at Cognitive Lode (consumer behaviour research curated and translated for product decision makers by Ribot, a design/creative agency).
This is called the Goal Gradient effect, it means that we would complete a task faster if it’s started for us. I think this should be helpful to people building fitness apps. No one likes to start with 0.